[PoC] XMLCast (SQL/XML X025)

From e30ded6ea7b3a18e2c26150ebd415a2853bad094 Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Fri, 5 Jul 2024 15:26:09 +0200
Subject: [PATCH v2] Add XMLCast function (SQL/XML X025)

This function implements the SQL/XML function xmlcast, which
enables conversions between SQL data types and the XML data type.

When casting an XML value to a SQL data type, XML values containing
XSD literals will be converted to their equivalent SQL data type.
When casting from a SQL data type to XML, the cast operand will be
translated to its corresponding XSD data type.

This patch also includes documentation and regression tests.
---
 doc/src/sgml/datatype.sgml            |  71 +++++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c |  83 ++++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  13 +-
 src/backend/parser/parse_expr.c       |  82 +++++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |   4 +
 src/backend/utils/adt/xml.c           |  29 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 326 ++++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 258 ++++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 326 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 152 ++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 1372 insertions(+), 8 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 6646820d6a..3bce8eb674 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4459,14 +4459,77 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option to convert character strings into xml is the function <function>xmlcast</function>,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. This can be useful for creating XML
+    documents using SQL or when parsing the contents of XML documents. The function <function>xmlcast</function> works with the
+    following criteria:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <literal>xml</literal>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <literal>xml</literal> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>s containing XML predifined entities
+          will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          The <replaceable>expression</replaceable>s of type <literal>date</literal>, <literal>time [with time zone]</literal>, <literal>timestamp [with time zone]</literal>,
+          and <literal>interval</literal> will be converted to their XSD equivalents, <literal>xs:date</literal>, <literal>xs:time</literal>,
+          <literal>xs:dateTime</literal>, and <literal>xs:duration</literal>, respectively.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index c002f37202..a4d8f7a2ac 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index d8735286c4..5a60627b6f 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4075,10 +4076,88 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/* These data types must be converted to their ISO 8601 representations */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/* INTERVAL data nust be converted to ISO 8601, e.g. '1 year 2 mons' -> 'P1Y2M' */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				default:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				}
+
+				*op->resnull = false;
+			}
 			break;
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
 	}
 }
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d2e2af4f81..66af81e2c2 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1726,6 +1726,9 @@ exprLocation(const Node *expr)
 			/* just use typename's location */
 			loc = exprLocation((Node *) ((const FunctionParameter *) expr)->argType);
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4421,6 +4424,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index a043fd4c66..38bc00cc37 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -795,7 +795,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -15909,6 +15909,15 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -17959,6 +17968,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18546,6 +18556,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 560b360644..4993e44110 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -42,6 +42,11 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -69,6 +74,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -276,6 +282,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2455,6 +2465,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2471,6 +2485,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index ee6fcd0503..0e68ee8bdf 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1947,6 +1947,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1973,6 +1976,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 653685bffc..6eb41411cb 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -9700,6 +9700,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -9746,6 +9749,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 3e4ca874d8..d357f458a6 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2659,6 +2659,35 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape characters in XML text nodes
+ */
+char *
+unescape_xml(const char *str)
+{
+#ifdef USE_LIBXML
+
+	volatile xmlParserCtxtPtr ctxt = NULL;
+	xmlChar *xmlbuf = NULL;
+	char *res;
+
+	ctxt = xmlNewParserCtxt();
+	xmlbuf = xmlStringDecodeEntities(ctxt, (xmlChar*) str, XML_SUBSTITUTE_REF, 0, 0, 0);
+
+	Assert(xmlbuf);
+
+	res = pstrdup((char *) xmlbuf);
+
+	xmlFree(xmlbuf);
+	xmlFreeParserCtxt(ctxt);
+
+	return res;
+#else
+	NO_XML_SUPPORT();
+	return NULL;
+#endif /* not USE_LIBXML */
+}
+
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 85a62b538e..578d83bc20 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -849,6 +849,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index ea47652adb..6c6f3591e6 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1577,6 +1577,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1613,6 +1614,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index f7fe834cf4..17065f36dc 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -505,6 +505,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index ed20e21375..78727a0d19 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 6500cff885..d4b1667564 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1862,3 +1862,329 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-07 | xml
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 9323b84ae2..ff8b470236 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1466,3 +1466,261 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index e1d165c6c9..94a5b00b61 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1842,3 +1842,329 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-07 | xml
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 953bac09e4..bce758e610 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -670,3 +670,155 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index e6c1caf649..e59838b967 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3224,6 +3224,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From 0679e82e9653183190a6af6c97de1887f567ef72 Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Thu, 15 Aug 2024 20:27:36 +0200
Subject: [PATCH v3] Add XMLCast function (SQL/XML X025)

This function implements the SQL/XML function xmlcast, which
enables conversions between SQL data types and the XML data type.

XMLCAST ( expression AS type [ BY REF | BY VALUE ] )

When casting an XML value to a SQL data type, XML values containing
XSD literals will be converted to their equivalent SQL data type.
When casting from a SQL data type to XML, the cast operand will be
translated to its corresponding XSD data type.

This patch also includes documentation and regression tests.
---
 doc/src/sgml/datatype.sgml            |  78 ++++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c |  83 ++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       |  81 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |   4 +
 src/backend/utils/adt/xml.c           |  29 ++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 429 ++++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 346 +++++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 429 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 210 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 1739 insertions(+), 8 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index e0d33f12e1..28c93460a5 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4472,14 +4472,84 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option to convert character strings into xml is the function <function>xmlcast</function>,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. This can be useful for creating XML
+    documents using SQL or when parsing the contents of XML documents. The function <function>xmlcast</function> works with the
+    following criteria:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <literal>xml</literal>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <literal>xml</literal> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>s containing XML predifined entities
+          will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          The <replaceable>expression</replaceable>s of type <literal>date</literal>, <literal>time [with time zone]</literal>, <literal>timestamp [with time zone]</literal>,
+          and <literal>interval</literal> will be converted to their XSD equivalents, <literal>xs:date</literal>, <literal>xs:time</literal>,
+          <literal>xs:dateTime</literal>, and <literal>xs:duration</literal>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index c002f37202..a4d8f7a2ac 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index ea47c4d6f9..1eb2231aa1 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4101,10 +4102,88 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/* These data types must be converted to their ISO 8601 representations */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/* INTERVAL data nust be converted to ISO 8601, e.g. '1 year 2 mons' -> 'P1Y2M' */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				default:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				}
+
+				*op->resnull = false;
+			}
 			break;
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
 	}
 }
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d2e2af4f81..66af81e2c2 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1726,6 +1726,9 @@ exprLocation(const Node *expr)
 			/* just use typename's location */
 			loc = exprLocation((Node *) ((const FunctionParameter *) expr)->argType);
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4421,6 +4424,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c3f25582c3..23b2928d9b 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -795,7 +795,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -15891,6 +15891,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -17940,6 +17958,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18526,6 +18545,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 56e413da9f..8e76d72c07 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -42,6 +42,10 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -69,6 +73,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -276,6 +281,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2456,6 +2465,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2472,6 +2485,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index ee6fcd0503..0e68ee8bdf 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1947,6 +1947,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1973,6 +1976,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 4039ee0df7..3c8e3baf32 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -9724,6 +9724,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -9770,6 +9773,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 447e72b21e..280fb58ab8 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2701,6 +2701,35 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape characters in XML text nodes
+ */
+char *
+unescape_xml(const char *str)
+{
+#ifdef USE_LIBXML
+
+	volatile xmlParserCtxtPtr ctxt = NULL;
+	xmlChar *xmlbuf = NULL;
+	char *res;
+
+	ctxt = xmlNewParserCtxt();
+	xmlbuf = xmlStringDecodeEntities(ctxt, (xmlChar*) str, XML_SUBSTITUTE_REF, 0, 0, 0);
+
+	Assert(xmlbuf);
+
+	res = pstrdup((char *) xmlbuf);
+
+	xmlFree(xmlbuf);
+	xmlFreeParserCtxt(ctxt);
+
+	return res;
+#else
+	NO_XML_SUPPORT();
+	return NULL;
+#endif /* not USE_LIBXML */
+}
+
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 85a62b538e..578d83bc20 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -849,6 +849,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index ea47652adb..6c6f3591e6 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1577,6 +1577,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1613,6 +1614,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index bb191b1f46..b17653cc2b 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -504,6 +504,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index ed20e21375..78727a0d19 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 93a79cda8f..b8aba206d4 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1853,3 +1853,432 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-07 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 9323b84ae2..cf1544a88a 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1466,3 +1466,349 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index f956322c69..80d6517fc7 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1839,3 +1839,432 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-07 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 953bac09e4..c7e597fbeb 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -670,3 +670,213 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 547d14b3e7..58aa3dad52 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3236,6 +3236,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From a43036de62a69c00d0c5c4469af02c8ded438530 Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Sun, 10 Nov 2024 16:13:18 +0100
Subject: [PATCH v4] Add XMLCast function (SQL/XML X025)

This function implements the SQL/XML function xmlcast, which
enables conversions between SQL data types and the XML data type.

XMLCAST ( expression AS type [ BY REF | BY VALUE ] )

When casting an XML value to a SQL data type, XML values containing
XSD literals will be converted to their equivalent SQL data type.
When casting from a SQL data type to XML, the cast operand will be
translated to its corresponding XSD data type.

This patch also includes documentation and regression tests.
---
 doc/src/sgml/datatype.sgml            |  78 ++++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c |  83 ++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       |  81 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |   4 +
 src/backend/utils/adt/xml.c           |  29 ++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 431 ++++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 348 +++++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 431 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 213 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 1748 insertions(+), 8 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index e0d33f12e1..28c93460a5 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4472,14 +4472,84 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option to convert character strings into xml is the function <function>xmlcast</function>,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. This can be useful for creating XML
+    documents using SQL or when parsing the contents of XML documents. The function <function>xmlcast</function> works with the
+    following criteria:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <literal>xml</literal>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <literal>xml</literal> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>s containing XML predifined entities
+          will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          The <replaceable>expression</replaceable>s of type <literal>date</literal>, <literal>time [with time zone]</literal>, <literal>timestamp [with time zone]</literal>,
+          and <literal>interval</literal> will be converted to their XSD equivalents, <literal>xs:date</literal>, <literal>xs:time</literal>,
+          <literal>xs:dateTime</literal>, and <literal>xs:duration</literal>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index c002f37202..a4d8f7a2ac 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 30c5a19aad..69a7bbae94 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4213,10 +4214,88 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/* These data types must be converted to their ISO 8601 representations */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/* INTERVAL data nust be converted to ISO 8601, e.g. '1 year 2 mons' -> 'P1Y2M' */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				default:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				}
+
+				*op->resnull = false;
+			}
 			break;
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
 	}
 }
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 3060847b13..f16a1475dc 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1725,6 +1725,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4434,6 +4437,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 67eb96396a..4d70c42f56 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -780,7 +780,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -15948,6 +15948,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -17998,6 +18016,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18583,6 +18602,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index c2806297aa..8651115b42 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,10 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +71,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -274,6 +279,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2454,6 +2463,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2470,6 +2483,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 76bf88c3ca..403ef683cd 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1956,6 +1956,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1982,6 +1985,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index a39068d1bf..150a047b99 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -9966,6 +9966,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10012,6 +10015,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 040a896263..cae7206037 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2722,6 +2722,35 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape characters in XML text nodes
+ */
+char *
+unescape_xml(const char *str)
+{
+#ifdef USE_LIBXML
+
+	volatile xmlParserCtxtPtr ctxt = NULL;
+	xmlChar *xmlbuf = NULL;
+	char *res;
+
+	ctxt = xmlNewParserCtxt();
+	xmlbuf = xmlStringDecodeEntities(ctxt, (xmlChar*) str, XML_SUBSTITUTE_REF, 0, 0, 0);
+
+	Assert(xmlbuf);
+
+	res = pstrdup((char *) xmlbuf);
+
+	xmlFree(xmlbuf);
+	xmlFreeParserCtxt(ctxt);
+
+	return res;
+#else
+	NO_XML_SUPPORT();
+	return NULL;
+#endif /* not USE_LIBXML */
+}
+
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0f9462493e..f904b39d88 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -851,6 +851,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index b0ef1952e8..f10729f4de 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1577,6 +1577,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1613,6 +1614,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 899d64ad55..18706dd84c 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -503,6 +503,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index ed20e21375..78727a0d19 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index fb5f345855..9477b7331a 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1869,3 +1869,434 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-08 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index ef7dc03c69..954453ea62 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1480,3 +1480,351 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index 4a9cdd2afe..fd94d5fa44 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1855,3 +1855,434 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-08 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index f752ecb142..d649bdb389 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -673,3 +673,216 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 1847bbfa95..98f9541324 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3244,6 +3244,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From f38c714220be8f2f4f939bedc46d8630ec5cd6dc Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Mon, 30 Dec 2024 09:57:05 +0100
Subject: [PATCH v5] Add XMLCast function (SQL/XML X025)

This implements the SQL/XML function xmlcast, which enables
conversions between SQL data types and the XML data type.

XMLCAST ( expression AS type [ BY REF | BY VALUE ] )

When casting an XML value to a SQL data type, XML values containing
XSD literals will be converted to their equivalent SQL data type.
When casting from a SQL data type to XML, the cast operand will be
translated to its corresponding XSD data type.

This patch also includes documentation and regression tests.
---
 doc/src/sgml/datatype.sgml            |  78 ++++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c |  83 ++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       |  81 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |   4 +
 src/backend/utils/adt/xml.c           |  61 ++++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 443 ++++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 354 ++++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 443 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 215 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 1812 insertions(+), 8 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 3e6751d64c..7673bec402 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4472,14 +4472,84 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option to convert character strings into xml is the function <function>xmlcast</function>,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. This can be useful for creating XML
+    documents using SQL or when parsing the contents of XML documents. The function <function>xmlcast</function> works with the
+    following criteria:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <literal>xml</literal>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <literal>xml</literal> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>s containing XML predifined entities
+          will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          The <replaceable>expression</replaceable>s of type <literal>date</literal>, <literal>time [with time zone]</literal>, <literal>timestamp [with time zone]</literal>,
+          and <literal>interval</literal> will be converted to their XSD equivalents, <literal>xs:date</literal>, <literal>xs:time</literal>,
+          <literal>xs:dateTime</literal>, and <literal>xs:duration</literal>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index c002f37202..a4d8f7a2ac 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index d2987663e6..d1d84f21b8 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4429,10 +4430,88 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/* These data types must be converted to their ISO 8601 representations */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/* INTERVAL data nust be converted to ISO 8601, e.g. '1 year 2 mons' -> 'P1Y2M' */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				default:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				}
+
+				*op->resnull = false;
+			}
 			break;
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
 	}
 }
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 50705a1e15..9f35d2cb94 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1725,6 +1725,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4434,6 +4437,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index bd5ebb35c4..b0ce33a532 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -780,7 +780,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -15948,6 +15948,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -17998,6 +18016,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18583,6 +18602,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index c2806297aa..8651115b42 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,10 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +71,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -274,6 +279,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2454,6 +2463,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2470,6 +2483,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 76bf88c3ca..403ef683cd 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1956,6 +1956,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1982,6 +1985,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index be1f1f50b7..6ae3b21a2a 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -9974,6 +9974,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10020,6 +10023,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 0898cb1be4..70ec2cc641 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2722,6 +2722,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0f9462493e..f904b39d88 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -851,6 +851,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index b0ef1952e8..f10729f4de 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1577,6 +1577,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1613,6 +1614,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 899d64ad55..18706dd84c 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -503,6 +503,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index ed20e21375..78727a0d19 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index fb5f345855..3dc11e9e69 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1869,3 +1869,446 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-08 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index ef7dc03c69..10deb57235 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1480,3 +1480,357 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index 4a9cdd2afe..0bc318521c 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1855,3 +1855,446 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-08 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index f752ecb142..92560e9989 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -673,3 +673,218 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index e1c4f913f8..8ab457123b 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3255,6 +3255,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From c81299327e30db88b8e990ceec817129c040f907 Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Fri, 21 Feb 2025 01:19:16 +0100
Subject: [PATCH v6] Add XMLCast function (SQL/XML X025)

This implements the SQL/XML function XMLCast, which enables
conversions between SQL data types and the XML data type.

XMLCAST ( expression AS type [ BY REF | BY VALUE ] )

When casting an XML value to a SQL data type, XML values containing
XSD literals will be converted to their equivalent SQL data type.
When casting from a SQL data type to XML, the cast operand will be
translated to its corresponding XSD data type.

This patch also includes documentation and regression tests.
---
 doc/src/sgml/datatype.sgml            |  78 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c |  83 +++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       |  81 ++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2201 insertions(+), 9 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 87679dc4a1..7e8bfaf1a1 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4487,14 +4487,84 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option to convert character strings into xml is the function <function>xmlcast</function>,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. This can be useful for creating XML
+    documents using SQL or when parsing the contents of XML documents. The function <function>xmlcast</function> works with the
+    following criteria:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <literal>xml</literal>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <literal>xml</literal> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>s containing XML predifined entities
+          will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          The <replaceable>expression</replaceable>s of type <literal>date</literal>, <literal>time [with time zone]</literal>, <literal>timestamp [with time zone]</literal>,
+          and <literal>interval</literal> will be converted to their XSD equivalents, <literal>xs:date</literal>, <literal>xs:time</literal>,
+          <literal>xs:dateTime</literal>, and <literal>xs:duration</literal>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 2f250d2c57..0b68e9b17f 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 1c3477b03c..8432846ec8 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4562,10 +4563,88 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/* These data types must be converted to their ISO 8601 representations */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/* INTERVAL data nust be converted to ISO 8601, e.g. '1 year 2 mons' -> 'P1Y2M' */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				default:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				}
+
+				*op->resnull = false;
+			}
 			break;
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
 	}
 }
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f..88c0a53e53 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1736,6 +1736,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4468,6 +4471,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 7d99c9355c..9591a97a56 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -788,7 +788,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16023,6 +16023,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18075,6 +18093,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18662,6 +18681,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index bad1df732e..50800ebe3b 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,10 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +71,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -274,6 +279,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2454,6 +2463,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2470,6 +2483,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d..6edc0a19c5 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1956,6 +1956,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1982,6 +1985,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 54dad97555..0a771d359e 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10029,6 +10029,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10039,7 +10042,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10075,6 +10078,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10145,6 +10149,10 @@ get_rule_expr(Node *node, deparse_context *context,
 					appendStringInfo(buf, " AS %s",
 									 format_type_with_typemod(xexpr->type,
 															  xexpr->typmod));
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index db8d0d6a7e..24fca428f6 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2722,6 +2722,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0b208f51bd..5cd5d42de7 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -860,6 +860,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 839e71d52f..00a28a0de4 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1582,6 +1582,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1618,6 +1619,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce6..40f412dab3 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -505,6 +505,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 0d7a816b9f..60bb464bd3 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 2e9616acda..f26d4897db 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1873,3 +1873,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-08 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST('11:11:11.5-08'::time with time zone::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |               c13                |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T03:04:10.703585-07:00 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 11:11:11.5-08
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AS c5,
+    XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AS c6,
+    XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AS c7,
+    XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AS c8,
+    XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AS c9,
+    XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |              c8              |              c9              |             c10              |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+------------------------------+------------------------------+------------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 09:30:10+00 | 09:30:10-06 | 09:30:10+06 | Thu May 30 02:30:10 2002 PDT | Thu May 30 08:30:10 2002 PDT | Wed May 29 20:30:10 2002 PDT | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 7505a14077..a18306c5fb 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1482,3 +1482,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index c07ed2b269..a02f518226 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1859,3 +1859,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-08 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST('11:11:11.5-08'::time with time zone::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |               c13                |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T03:04:10.703585-07:00 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 11:11:11.5-08
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AS c5,
+    XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AS c6,
+    XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AS c7,
+    XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AS c8,
+    XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AS c9,
+    XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |              c8              |              c9              |             c10              |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+------------------------------+------------------------------+------------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 09:30:10+00 | 09:30:10-06 | 09:30:10+06 | Thu May 30 02:30:10 2002 PDT | Thu May 30 08:30:10 2002 PDT | Wed May 29 20:30:10 2002 PDT | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index bac0388ac1..eed9299086 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -675,3 +675,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 98ab45adfa..3731f43ac5 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3274,6 +3274,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From ece6a7421fc8a250d8da14c89817774802508b10 Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Fri, 21 Feb 2025 11:27:09 +0100
Subject: [PATCH v7] Add XMLCast function (SQL/XML X025)

This implements the SQL/XML function XMLCast, which enables
conversions between SQL data types and the XML data type.

XMLCAST ( expression AS type [ BY REF | BY VALUE ] )

When casting an XML value to a SQL data type, XML values containing
XSD literals will be converted to their equivalent SQL data type.
When casting from a SQL data type to XML, the cast operand will be
translated to its corresponding XSD data type.

This patch also includes documentation and regression tests.
---
 doc/src/sgml/datatype.sgml            |  78 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c |  83 +++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       |  81 ++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2201 insertions(+), 9 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 87679dc4a1..7e8bfaf1a1 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4487,14 +4487,84 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option to convert character strings into xml is the function <function>xmlcast</function>,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. This can be useful for creating XML
+    documents using SQL or when parsing the contents of XML documents. The function <function>xmlcast</function> works with the
+    following criteria:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <literal>xml</literal>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <literal>xml</literal> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>s containing XML predifined entities
+          will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          The <replaceable>expression</replaceable>s of type <literal>date</literal>, <literal>time [with time zone]</literal>, <literal>timestamp [with time zone]</literal>,
+          and <literal>interval</literal> will be converted to their XSD equivalents, <literal>xs:date</literal>, <literal>xs:time</literal>,
+          <literal>xs:dateTime</literal>, and <literal>xs:duration</literal>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 2f250d2c57..0b68e9b17f 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 1c3477b03c..8432846ec8 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4562,10 +4563,88 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/* These data types must be converted to their ISO 8601 representations */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/* INTERVAL data nust be converted to ISO 8601, e.g. '1 year 2 mons' -> 'P1Y2M' */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				default:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				}
+
+				*op->resnull = false;
+			}
 			break;
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
 	}
 }
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f..88c0a53e53 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1736,6 +1736,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4468,6 +4471,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 7d99c9355c..9591a97a56 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -788,7 +788,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16023,6 +16023,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18075,6 +18093,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18662,6 +18681,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index bad1df732e..50800ebe3b 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,10 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +71,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -274,6 +279,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2454,6 +2463,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2470,6 +2483,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d..6edc0a19c5 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1956,6 +1956,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1982,6 +1985,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d11a8a20ee..ced41b24de 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10029,6 +10029,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10039,7 +10042,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10075,6 +10078,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10152,6 +10156,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index db8d0d6a7e..24fca428f6 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2722,6 +2722,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0b208f51bd..5cd5d42de7 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -860,6 +860,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 839e71d52f..00a28a0de4 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1582,6 +1582,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1618,6 +1619,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce6..40f412dab3 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -505,6 +505,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 0d7a816b9f..60bb464bd3 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index bcc743f485..37c4328700 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1877,3 +1877,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-08 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST('11:11:11.5-08'::time with time zone::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |               c13                |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T03:04:10.703585-07:00 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 11:11:11.5-08
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AS c5,
+    XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AS c6,
+    XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AS c7,
+    XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AS c8,
+    XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AS c9,
+    XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |              c8              |              c9              |             c10              |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+------------------------------+------------------------------+------------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 09:30:10+00 | 09:30:10-06 | 09:30:10+06 | Thu May 30 02:30:10 2002 PDT | Thu May 30 08:30:10 2002 PDT | Wed May 29 20:30:10 2002 PDT | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index a1c5d31417..8794cddbe1 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1492,3 +1492,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index 045641dae6..a9849fc7c0 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1863,3 +1863,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+                j                 | pg_typeof 
+----------------------------------+-----------
+ 2024-05-29T03:04:10.703585-07:00 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 11:11:11.5-08 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST('11:11:11.5-08'::time with time zone::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |               c13                |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T03:04:10.703585-07:00 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 11:11:11.5-08
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AS c5,
+    XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AS c6,
+    XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AS c7,
+    XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AS c8,
+    XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AS c9,
+    XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |              c8              |              c9              |             c10              |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+------------------------------+------------------------------+------------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 09:30:10+00 | 09:30:10-06 | 09:30:10+06 | Thu May 30 02:30:10 2002 PDT | Thu May 30 08:30:10 2002 PDT | Wed May 29 20:30:10 2002 PDT | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 4c3520ce89..b3a1b19a93 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -677,3 +677,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b09d8af718..f5336a5d10 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3284,6 +3284,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From d8627405b82f56117afa44b96e970a44684d45ca Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Mon, 10 Mar 2025 10:17:48 +0100
Subject: [PATCH v8] Add XMLCast function (SQL/XML X025)

This implements the SQL/XML function XMLCast, which enables
conversions between SQL data types and the XML data type.

XMLCAST ( expression AS type [ BY REF | BY VALUE ] )

When casting an XML value to a SQL data type, XML values containing
XSD literals will be converted to their equivalent SQL data type.
When casting from a SQL data type to XML, the cast operand will be
translated to its corresponding XSD data type.

This patch also includes documentation and regression tests.
---
 doc/src/sgml/datatype.sgml            |  78 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c |  83 +++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       |  81 ++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2201 insertions(+), 9 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 09309ba039..f1b2f91924 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4496,14 +4496,84 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option to convert character strings into xml is the function <function>xmlcast</function>,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. This can be useful for creating XML
+    documents using SQL or when parsing the contents of XML documents. The function <function>xmlcast</function> works with the
+    following criteria:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <literal>xml</literal>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <literal>xml</literal> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>s containing XML predifined entities
+          will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          The <replaceable>expression</replaceable>s of type <literal>date</literal>, <literal>time [with time zone]</literal>, <literal>timestamp [with time zone]</literal>,
+          and <literal>interval</literal> will be converted to their XSD equivalents, <literal>xs:date</literal>, <literal>xs:time</literal>,
+          <literal>xs:dateTime</literal>, and <literal>xs:duration</literal>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 2f250d2c57..0b68e9b17f 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 1c3477b03c..8432846ec8 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4562,10 +4563,88 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/* These data types must be converted to their ISO 8601 representations */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/* INTERVAL data nust be converted to ISO 8601, e.g. '1 year 2 mons' -> 'P1Y2M' */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				default:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				}
+
+				*op->resnull = false;
+			}
 			break;
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
 	}
 }
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f..88c0a53e53 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1736,6 +1736,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4468,6 +4471,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 271ae26cba..1fe495cee5 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -788,7 +788,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16051,6 +16051,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18103,6 +18121,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18690,6 +18709,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index bad1df732e..50800ebe3b 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,10 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +71,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -274,6 +279,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2454,6 +2463,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2470,6 +2483,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d..6edc0a19c5 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1956,6 +1956,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1982,6 +1985,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d11a8a20ee..ced41b24de 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10029,6 +10029,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10039,7 +10042,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10075,6 +10078,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10152,6 +10156,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index db8d0d6a7e..24fca428f6 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2722,6 +2722,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 23c9e3c5ab..114987d20a 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -860,6 +860,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index d0576da3e2..ef80b3511e 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1582,6 +1582,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1618,6 +1619,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce6..40f412dab3 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -505,6 +505,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 0d7a816b9f..60bb464bd3 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index bcc743f485..aaf851adb2 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1877,3 +1877,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 19:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 19:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index a1c5d31417..fc110ae26c 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1492,3 +1492,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index 045641dae6..808d73fde4 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1863,3 +1863,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 19:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 19:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 4c3520ce89..9ec5f6c070 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -677,3 +677,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9840060997..5342414894 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3293,6 +3293,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From 407ef65a398aa2d968d7b3d7d86548e3edcddd99 Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Mon, 19 May 2025 14:57:27 +0200
Subject: [PATCH v9] Add XMLCast function (SQL/XML X025)

This implements the SQL/XML function XMLCast, which enables
conversions between SQL data types and the XML data type.

XMLCAST ( expression AS type [ BY REF | BY VALUE ] )

When casting an XML value to a SQL data type, XML values containing
XSD literals will be converted to their equivalent SQL data type.
When casting from a SQL data type to XML, the cast operand will be
translated to its corresponding XSD data type.

This patch also includes documentation and regression tests.
---
 doc/src/sgml/datatype.sgml            |  78 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c |  83 +++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       |  81 ++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2201 insertions(+), 9 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 09309ba039..f1b2f91924 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4496,14 +4496,84 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option to convert character strings into xml is the function <function>xmlcast</function>,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. This can be useful for creating XML
+    documents using SQL or when parsing the contents of XML documents. The function <function>xmlcast</function> works with the
+    following criteria:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <literal>xml</literal>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <literal>xml</literal> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>s containing XML predifined entities
+          will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          The <replaceable>expression</replaceable>s of type <literal>date</literal>, <literal>time [with time zone]</literal>, <literal>timestamp [with time zone]</literal>,
+          and <literal>interval</literal> will be converted to their XSD equivalents, <literal>xs:date</literal>, <literal>xs:time</literal>,
+          <literal>xs:dateTime</literal>, and <literal>xs:duration</literal>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index ebe85337c2..5f34d95d64 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 8a72b5e70a..a1c2e529f1 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,10 +4644,88 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/* These data types must be converted to their ISO 8601 representations */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/* INTERVAL data nust be converted to ISO 8601, e.g. '1 year 2 mons' -> 'P1Y2M' */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				default:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				}
+
+				*op->resnull = false;
+			}
 			break;
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
 	}
 }
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f..88c0a53e53 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1736,6 +1736,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4468,6 +4471,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 0b5652071d..5767a69219 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -788,7 +788,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16053,6 +16053,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18106,6 +18124,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18694,6 +18713,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 1f8e2d5467..6041248b6c 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,10 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +71,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -274,6 +279,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2462,6 +2471,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2478,6 +2491,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d..6edc0a19c5 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1956,6 +1956,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1982,6 +1985,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 467b08198b..cd5581b6ef 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10081,6 +10081,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10091,7 +10094,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10127,6 +10130,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10204,6 +10208,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index db8d0d6a7e..24fca428f6 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2722,6 +2722,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 4610fc6129..d3d82a6e7f 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -860,6 +860,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 7d3b4198f2..8cc25f7f56 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1582,6 +1582,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1618,6 +1619,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index a4af3f717a..65750625b1 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -506,6 +506,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 0d7a816b9f..60bb464bd3 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..9ba5400d2b 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+02 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+02
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 11:30:10+02 | 17:30:10+02 | 05:30:10+02 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..40d642d59d 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..520329fbcb 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+02 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+02
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 11:30:10+02 | 17:30:10+02 | 05:30:10+02 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..1fae5b4b00 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9ea573fae2..ab1dc2a9bd 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3355,6 +3355,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From 9c72a8e9d10d82564dc419db3f33d711878bbbb4 Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Tue, 20 May 2025 00:34:51 +0200
Subject: [PATCH v10] Add XMLCast function (SQL/XML X025)

This patch introduces support for the XMLCAST function, as specified
in SQL/XML:2023 (ISO/IEC 9075-14:2023), Subclause 6.7 "<XML cast
specification>". It enables standards-compliant conversion between
SQL data types and XML, following the lexical rules defined by the
W3C XML Schema Part 2.

XMLCAST provides an alternative to CAST when converting SQL values
into XML content, ensuring the output uses canonical XML Schema
lexical representations. For example, timestamp and interval values
are rendered as `xs:dateTime` and `xs:duration` (e.g.,
"2024-01-01T12:00:00Z" or "P1Y2M"), conforming to ISO 8601 formats.

Conversely, XMLCAST also allows converting XML content back into SQL
types (e.g., boolean, numeric, date/time), validating the input string
according to XML Schema lexical forms.

Supported casts include:
  - SQL -> XML: boolean, numeric, character, date/time, interval
  - XML -> SQL: the inverse of the above, with lexical validation

The BY REF and BY VALUE clauses are accepted for SQL/XML compatibility,
but ignored.

Documentation and regression tests are included.
---
 doc/src/sgml/datatype.sgml            |  87 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c | 123 +++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       |  81 ++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2249 insertions(+), 10 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 09309ba039..7f91ad3aee 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4496,14 +4496,93 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option for converting values to or from <type>xml</type> is the <function>xmlcast</function> function,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa, in a standards-compliant way.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. It is primarily used for converting between SQL values
+    and <type>xml</type> values in a standards-compliant way.
+
+    Unlike <function>CAST</function>, which may coerce SQL values into text or XML without enforcing a specific
+    lexical representation, <function>xmlcast</function> ensures that the conversion produces or expects a
+    canonical XML Schema lexical form appropriate for the target type. For example, an <type>interval</type>
+    value is rendered as <literal>P1Y2M</literal> (<type>xs:duration</type>), and a <type>timestamp</type> as
+    <literal>2023-05-19T14:30:00Z</literal> (xs:dateTime). Similarly, when converting from XML to SQL types,
+    <function>xmlcast</function> validates that the input string conforms to the lexical format required by the
+    corresponding SQL type.
+
+    The function <function>xmlcast</function> follows these rules:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <type>xml</type>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <type>xml</type> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>
+          values containing XML predefined entities will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Values of type <type>date</type>, <type>time with time zone</type>, <type>timestamp with time zone</type>,
+          and <type>interval</type> are converted to their corresponding XML Schema types: <type>xs:date</type>,
+          <type>xs:time</type>, <type>xs:dateTime</type>, and <type>xs:duration</type>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index ebe85337c2..5f34d95d64 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 8a72b5e70a..9cc0e07cca 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,11 +4644,127 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/*
+					 * SQL date/time types must be mapped to XML Schema types when casting to XML:
+					 *   - DATE                        -> xs:date
+					 *   - TIME [WITH/WITHOUT TZ]      -> xs:time
+					 *   - TIMESTAMP [WITH/WITHOUT TZ] -> xs:dateTime
+					 *
+					 * These mappings are defined in SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", item 15.e.i–v.
+					 *
+					 * The corresponding XML Schema lexical formats (e.g., "2023-05-19", "14:30:00Z",
+					 * "2023-05-19T14:30:00+01:00") follow ISO 8601 and are specified in
+					 * W3C XML Schema Part 2: Primitive Datatypes §3.2.7 (dateTime) and §3.2.9 (date).
+					 */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/*
+					 * SQL interval types must be mapped to XML Schema types when casting to XML:
+					 *   - Year-month intervals → xs:yearMonthDuration
+					 *   - Day-time intervals   → xs:dayTimeDuration
+					 *
+					 * This behavior is required by SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii.1–2.
+					 *
+					 * These XML Schema types require ISO 8601-compatible lexical representations,
+					 * such as: "P1Y2M", "P3DT4H5M", or "P1Y2M3DT4H5M6S", as defined in
+					 * W3C XML Schema Part 2: Primitve Datatypes, §3.2.6 (duration)
+					 */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				case INT2OID:
+				case INT4OID:
+				case INT8OID:
+				case NUMERICOID:
+				case FLOAT4OID:
+				case FLOAT8OID:
+				case BOOLOID:
+				case TIMESTAMPOID:
+				case TIMESTAMPTZOID:
+				case TIMEOID:
+				case TIMETZOID:
+				case DATEOID:
+				case BYTEAOID:
+				case INTERVALOID:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				default:
+					elog(ERROR, "unsupported target data type for XMLCast");
+				}
+
+				*op->resnull = false;
+			}
 			break;
-	}
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
+			}
 }
 
 /*
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f..88c0a53e53 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1736,6 +1736,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4468,6 +4471,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 0b5652071d..5767a69219 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -788,7 +788,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16053,6 +16053,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18106,6 +18124,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18694,6 +18713,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 1f8e2d5467..6041248b6c 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,10 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC || (x) == TYPCATEGORY_STRING \
+			|| (x) == TYPCATEGORY_DATETIME || (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +71,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -274,6 +279,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2462,6 +2471,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2478,6 +2491,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	/*
+	 * we make sure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * it is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as TEXT and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d..6edc0a19c5 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1956,6 +1956,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1982,6 +1985,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 467b08198b..cd5581b6ef 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10081,6 +10081,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10091,7 +10094,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10127,6 +10130,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10204,6 +10208,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index db8d0d6a7e..24fca428f6 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2722,6 +2722,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 4610fc6129..d3d82a6e7f 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -860,6 +860,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 7d3b4198f2..8cc25f7f56 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1582,6 +1582,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1618,6 +1619,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index a4af3f717a..65750625b1 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -506,6 +506,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 0d7a816b9f..60bb464bd3 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..9ba5400d2b 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+02 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+02
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 11:30:10+02 | 17:30:10+02 | 05:30:10+02 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..40d642d59d 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..520329fbcb 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+02 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+02
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 11:30:10+02 | 17:30:10+02 | 05:30:10+02 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..1fae5b4b00 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9ea573fae2..ab1dc2a9bd 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3355,6 +3355,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From 2b842d723aefd5b8bed976a0d774b2bc9aacb2db Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Fri, 23 May 2025 11:43:44 +0200
Subject: [PATCH v11] Add XMLCast function (SQL/XML X025)

This patch introduces support for the XMLCAST function, as specified
in SQL/XML:2023 (ISO/IEC 9075-14:2023), Subclause 6.7 "<XML cast
specification>". It enables standards-compliant conversion between
SQL data types and XML, following the lexical rules defined by the
W3C XML Schema Part 2.

XMLCast provides an alternative to CAST when converting SQL values
into XML content, ensuring the output uses canonical XML Schema
lexical representations. For example, timestamp and interval values
are rendered as `xs:dateTime` and `xs:duration` (e.g.,
"2024-01-01T12:00:00Z" or "P1Y2M"), conforming to ISO 8601 formats.

Conversely, XMLCast also allows converting XML content back into SQL
types (e.g., boolean, numeric, date/time), validating the input string
according to XML Schema lexical forms.

Supported casts include:
  - SQL -> XML: boolean, numeric, character, date/time, interval
  - XML -> SQL: the inverse of the above, with lexical validation

The BY REF and BY VALUE clauses are accepted for SQL/XML compatibility,
but ignored.

Documentation and regression tests are included.
---
 doc/src/sgml/datatype.sgml            |  87 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c | 123 +++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       | 108 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2276 insertions(+), 10 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 09309ba039..7f91ad3aee 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4496,14 +4496,93 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option for converting values to or from <type>xml</type> is the <function>xmlcast</function> function,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa, in a standards-compliant way.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. It is primarily used for converting between SQL values
+    and <type>xml</type> values in a standards-compliant way.
+
+    Unlike <function>CAST</function>, which may coerce SQL values into text or XML without enforcing a specific
+    lexical representation, <function>xmlcast</function> ensures that the conversion produces or expects a
+    canonical XML Schema lexical form appropriate for the target type. For example, an <type>interval</type>
+    value is rendered as <literal>P1Y2M</literal> (<type>xs:duration</type>), and a <type>timestamp</type> as
+    <literal>2023-05-19T14:30:00Z</literal> (xs:dateTime). Similarly, when converting from XML to SQL types,
+    <function>xmlcast</function> validates that the input string conforms to the lexical format required by the
+    corresponding SQL type.
+
+    The function <function>xmlcast</function> follows these rules:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <type>xml</type>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <type>xml</type> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>
+          values containing XML predefined entities will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Values of type <type>date</type>, <type>time with time zone</type>, <type>timestamp with time zone</type>,
+          and <type>interval</type> are converted to their corresponding XML Schema types: <type>xs:date</type>,
+          <type>xs:time</type>, <type>xs:dateTime</type>, and <type>xs:duration</type>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index ebe85337c2..5f34d95d64 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 8a72b5e70a..9cc0e07cca 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,11 +4644,127 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/*
+					 * SQL date/time types must be mapped to XML Schema types when casting to XML:
+					 *   - DATE                        -> xs:date
+					 *   - TIME [WITH/WITHOUT TZ]      -> xs:time
+					 *   - TIMESTAMP [WITH/WITHOUT TZ] -> xs:dateTime
+					 *
+					 * These mappings are defined in SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", item 15.e.i–v.
+					 *
+					 * The corresponding XML Schema lexical formats (e.g., "2023-05-19", "14:30:00Z",
+					 * "2023-05-19T14:30:00+01:00") follow ISO 8601 and are specified in
+					 * W3C XML Schema Part 2: Primitive Datatypes §3.2.7 (dateTime) and §3.2.9 (date).
+					 */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/*
+					 * SQL interval types must be mapped to XML Schema types when casting to XML:
+					 *   - Year-month intervals → xs:yearMonthDuration
+					 *   - Day-time intervals   → xs:dayTimeDuration
+					 *
+					 * This behavior is required by SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii.1–2.
+					 *
+					 * These XML Schema types require ISO 8601-compatible lexical representations,
+					 * such as: "P1Y2M", "P3DT4H5M", or "P1Y2M3DT4H5M6S", as defined in
+					 * W3C XML Schema Part 2: Primitve Datatypes, §3.2.6 (duration)
+					 */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				case INT2OID:
+				case INT4OID:
+				case INT8OID:
+				case NUMERICOID:
+				case FLOAT4OID:
+				case FLOAT8OID:
+				case BOOLOID:
+				case TIMESTAMPOID:
+				case TIMESTAMPTZOID:
+				case TIMEOID:
+				case TIMETZOID:
+				case DATEOID:
+				case BYTEAOID:
+				case INTERVALOID:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				default:
+					elog(ERROR, "unsupported target data type for XMLCast");
+				}
+
+				*op->resnull = false;
+			}
 			break;
-	}
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
+			}
 }
 
 /*
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f..88c0a53e53 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1736,6 +1736,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4468,6 +4471,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 0b5652071d..5767a69219 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -788,7 +788,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16053,6 +16053,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18106,6 +18124,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18694,6 +18713,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 1f8e2d5467..93ededc6b4 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,37 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+/*
+ * Determines whether a type category is allowed in XMLCAST conversions,
+ * either as a source (SQL -> XML) or target (XML -> SQL) type.
+ *
+ * Based on SQL/XML:2023 (ISO/IEC 9075-14:2023),
+ * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii:
+ *
+ * - Items 1–2 explicitly describe interval mappings:
+ *     1) Year-month intervals -> xs:yearMonthDuration
+ *     2) Day-time intervals   -> xs:dayTimeDuration
+ *
+ * - Items 3–4 describe the general case:
+ *     3) If the target XML type is an XML Schema built-in data type,
+ *     or
+ *     4) If it is derived from a built-in atomic type,
+ *     then that type (or its base type) governs the conversion.
+ *
+ * These built-in and atomic types are defined in "W3C XML Schema Part 2:
+ * Datatypes", and include types such as xs:boolean, xs:decimal, xs:date,
+ * xs:dateTime, and xs:string. While SQL/XML does not enumerate mappings
+ * for all these types, it relies on their existence and semantics to
+ * support conversions.
+ *
+ * As such, PostgreSQL allows casting to and from types in the following
+ * categories: numeric, string, datetime, boolean, and timespan.
+ */
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC \
+			|| (x) == TYPCATEGORY_STRING || (x) == TYPCATEGORY_DATETIME \
+			|| (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +98,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -274,6 +306,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2462,6 +2498,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2478,6 +2518,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	/*
+	 * Ensure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * It is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as text and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d..6edc0a19c5 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1956,6 +1956,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1982,6 +1985,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 3d6e6bdbfd..5894b892c9 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10091,6 +10091,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10101,7 +10104,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10137,6 +10140,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10214,6 +10218,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index a4150bff2e..20bfedc503 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2735,6 +2735,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 4610fc6129..d3d82a6e7f 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -860,6 +860,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 7d3b4198f2..8cc25f7f56 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1582,6 +1582,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1618,6 +1619,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index a4af3f717a..65750625b1 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -506,6 +506,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 0d7a816b9f..60bb464bd3 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..9ba5400d2b 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+02 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+02
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 11:30:10+02 | 17:30:10+02 | 05:30:10+02 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..40d642d59d 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..520329fbcb 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+02 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+02
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 11:30:10+02 | 17:30:10+02 | 05:30:10+02 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..1fae5b4b00 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9ea573fae2..ab1dc2a9bd 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3355,6 +3355,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.34.1

From f9df728500dd281b6651b22fd62ef6586b58453a Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Mon, 27 Oct 2025 13:19:14 +0100
Subject: [PATCH v12] Add XMLCast function (SQL/XML X025)

This patch introduces support for the XMLCAST function, as specified
in SQL/XML:2023 (ISO/IEC 9075-14:2023), Subclause 6.7 "<XML cast
specification>". It enables standards-compliant conversion between
SQL data types and XML, following the lexical rules defined by the
W3C XML Schema Part 2.

XMLCast provides an alternative to CAST when converting SQL values
into XML content, ensuring the output uses canonical XML Schema
lexical representations. For example, timestamp and interval values
are rendered as `xs:dateTime` and `xs:duration` (e.g.,
"2024-01-01T12:00:00Z" or "P1Y2M"), conforming to ISO 8601 formats.

Conversely, XMLCast also allows converting XML content back into SQL
types (e.g., boolean, numeric, date/time), validating the input string
according to XML Schema lexical forms.

Supported casts include:
  - SQL -> XML: boolean, numeric, character, date/time, interval
  - XML -> SQL: the inverse of the above, with lexical validation

The BY REF and BY VALUE clauses are accepted for SQL/XML compatibility,
but ignored.

Documentation and regression tests are included.
---
 doc/src/sgml/datatype.sgml            |  87 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c | 123 +++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       | 108 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2276 insertions(+), 10 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index b81d89e260..bff8082160 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4494,14 +4494,93 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option for converting values to or from <type>xml</type> is the <function>xmlcast</function> function,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa, in a standards-compliant way.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. It is primarily used for converting between SQL values
+    and <type>xml</type> values in a standards-compliant way.
+
+    Unlike <function>CAST</function>, which may coerce SQL values into text or XML without enforcing a specific
+    lexical representation, <function>xmlcast</function> ensures that the conversion produces or expects a
+    canonical XML Schema lexical form appropriate for the target type. For example, an <type>interval</type>
+    value is rendered as <literal>P1Y2M</literal> (<type>xs:duration</type>), and a <type>timestamp</type> as
+    <literal>2023-05-19T14:30:00Z</literal> (xs:dateTime). Similarly, when converting from XML to SQL types,
+    <function>xmlcast</function> validates that the input string conforms to the lexical format required by the
+    corresponding SQL type.
+
+    The function <function>xmlcast</function> follows these rules:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <type>xml</type>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <type>xml</type> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>
+          values containing XML predefined entities will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Values of type <type>date</type>, <type>time with time zone</type>, <type>timestamp with time zone</type>,
+          and <type>interval</type> are converted to their corresponding XML Schema types: <type>xs:date</type>,
+          <type>xs:time</type>, <type>xs:dateTime</type>, and <type>xs:duration</type>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 3a8ad20160..412e1a4e37 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 0e1a74976f..246abaf544 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,11 +4644,127 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/*
+					 * SQL date/time types must be mapped to XML Schema types when casting to XML:
+					 *   - DATE                        -> xs:date
+					 *   - TIME [WITH/WITHOUT TZ]      -> xs:time
+					 *   - TIMESTAMP [WITH/WITHOUT TZ] -> xs:dateTime
+					 *
+					 * These mappings are defined in SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", item 15.e.i–v.
+					 *
+					 * The corresponding XML Schema lexical formats (e.g., "2023-05-19", "14:30:00Z",
+					 * "2023-05-19T14:30:00+01:00") follow ISO 8601 and are specified in
+					 * W3C XML Schema Part 2: Primitive Datatypes §3.2.7 (dateTime) and §3.2.9 (date).
+					 */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/*
+					 * SQL interval types must be mapped to XML Schema types when casting to XML:
+					 *   - Year-month intervals → xs:yearMonthDuration
+					 *   - Day-time intervals   → xs:dayTimeDuration
+					 *
+					 * This behavior is required by SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii.1–2.
+					 *
+					 * These XML Schema types require ISO 8601-compatible lexical representations,
+					 * such as: "P1Y2M", "P3DT4H5M", or "P1Y2M3DT4H5M6S", as defined in
+					 * W3C XML Schema Part 2: Primitve Datatypes, §3.2.6 (duration)
+					 */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				case INT2OID:
+				case INT4OID:
+				case INT8OID:
+				case NUMERICOID:
+				case FLOAT4OID:
+				case FLOAT8OID:
+				case BOOLOID:
+				case TIMESTAMPOID:
+				case TIMESTAMPTZOID:
+				case TIMEOID:
+				case TIMETZOID:
+				case DATEOID:
+				case BYTEAOID:
+				case INTERVALOID:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				default:
+					elog(ERROR, "unsupported target data type for XMLCast");
+				}
+
+				*op->resnull = false;
+			}
 			break;
-	}
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
+			}
 }
 
 /*
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index ede838cd40..8994bdda8e 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1732,6 +1732,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4464,6 +4467,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index a4b29c822e..8a599f9641 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -794,7 +794,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16144,6 +16144,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18195,6 +18213,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18783,6 +18802,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 12119f147f..34a2925e0e 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,37 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+/*
+ * Determines whether a type category is allowed in XMLCAST conversions,
+ * either as a source (SQL -> XML) or target (XML -> SQL) type.
+ *
+ * Based on SQL/XML:2023 (ISO/IEC 9075-14:2023),
+ * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii:
+ *
+ * - Items 1–2 explicitly describe interval mappings:
+ *     1) Year-month intervals -> xs:yearMonthDuration
+ *     2) Day-time intervals   -> xs:dayTimeDuration
+ *
+ * - Items 3–4 describe the general case:
+ *     3) If the target XML type is an XML Schema built-in data type,
+ *     or
+ *     4) If it is derived from a built-in atomic type,
+ *     then that type (or its base type) governs the conversion.
+ *
+ * These built-in and atomic types are defined in "W3C XML Schema Part 2:
+ * Datatypes", and include types such as xs:boolean, xs:decimal, xs:date,
+ * xs:dateTime, and xs:string. While SQL/XML does not enumerate mappings
+ * for all these types, it relies on their existence and semantics to
+ * support conversions.
+ *
+ * As such, PostgreSQL allows casting to and from types in the following
+ * categories: numeric, string, datetime, boolean, and timespan.
+ */
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC \
+			|| (x) == TYPCATEGORY_STRING || (x) == TYPCATEGORY_DATETIME \
+			|| (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +98,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -275,6 +307,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2467,6 +2503,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2483,6 +2523,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	/*
+	 * Ensure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * It is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as text and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 905c975d83..4b2fee64cb 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1955,6 +1955,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1981,6 +1984,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 79ec136231..c708be1ebd 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10115,6 +10115,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10125,7 +10128,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10161,6 +10164,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10238,6 +10242,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 66b4418369..918f88397d 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2762,6 +2762,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index ecbddd12e1..4da08cd152 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -877,6 +877,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1b4436f2ff..77c1be8ff0 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1602,6 +1602,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1638,6 +1639,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 84182eaaae..25306eddf0 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -508,6 +508,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 0d7a816b9f..60bb464bd3 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..a425109f71 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 19:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 19:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..40d642d59d 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..adb0ac0ab2 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 19:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-07'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 19:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..1fae5b4b00 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 43fe3bcd59..2e481cd8d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3383,6 +3383,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.43.0

From cf3e2c7f1ba28049d3912b8ef4b3f79ae1ef83bd Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Mon, 3 Nov 2025 09:03:40 +0100
Subject: [PATCH v13] Add XMLCast function (SQL/XML X025)

This patch introduces support for the XMLCAST function, as specified
in SQL/XML:2023 (ISO/IEC 9075-14:2023), Subclause 6.7 "<XML cast
specification>". It enables standards-compliant conversion between
SQL data types and XML, following the lexical rules defined by the
W3C XML Schema Part 2.

XMLCast provides an alternative to CAST when converting SQL values
into XML content, ensuring the output uses canonical XML Schema
lexical representations. For example, timestamp and interval values
are rendered as `xs:dateTime` and `xs:duration` (e.g.,
"2024-01-01T12:00:00Z" or "P1Y2M"), conforming to ISO 8601 formats.

Conversely, XMLCast also allows converting XML content back into SQL
types (e.g., boolean, numeric, date/time), validating the input string
according to XML Schema lexical forms.

Supported casts include:
  - SQL -> XML: boolean, numeric, character, date/time, interval
  - XML -> SQL: the inverse of the above, with lexical validation

The BY REF and BY VALUE clauses are accepted for SQL/XML compatibility,
but ignored.

Documentation and regression tests are included.
---
 doc/src/sgml/datatype.sgml            |  87 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c | 123 +++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       | 108 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2276 insertions(+), 10 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index b81d89e260..bff8082160 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4494,14 +4494,93 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option for converting values to or from <type>xml</type> is the <function>xmlcast</function> function,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa, in a standards-compliant way.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. It is primarily used for converting between SQL values
+    and <type>xml</type> values in a standards-compliant way.
+
+    Unlike <function>CAST</function>, which may coerce SQL values into text or XML without enforcing a specific
+    lexical representation, <function>xmlcast</function> ensures that the conversion produces or expects a
+    canonical XML Schema lexical form appropriate for the target type. For example, an <type>interval</type>
+    value is rendered as <literal>P1Y2M</literal> (<type>xs:duration</type>), and a <type>timestamp</type> as
+    <literal>2023-05-19T14:30:00Z</literal> (xs:dateTime). Similarly, when converting from XML to SQL types,
+    <function>xmlcast</function> validates that the input string conforms to the lexical format required by the
+    corresponding SQL type.
+
+    The function <function>xmlcast</function> follows these rules:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <type>xml</type>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <type>xml</type> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>
+          values containing XML predefined entities will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Values of type <type>date</type>, <type>time with time zone</type>, <type>timestamp with time zone</type>,
+          and <type>interval</type> are converted to their corresponding XML Schema types: <type>xs:date</type>,
+          <type>xs:time</type>, <type>xs:dateTime</type>, and <type>xs:duration</type>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 3a8ad20160..412e1a4e37 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 0e1a74976f..246abaf544 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,11 +4644,127 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/*
+					 * SQL date/time types must be mapped to XML Schema types when casting to XML:
+					 *   - DATE                        -> xs:date
+					 *   - TIME [WITH/WITHOUT TZ]      -> xs:time
+					 *   - TIMESTAMP [WITH/WITHOUT TZ] -> xs:dateTime
+					 *
+					 * These mappings are defined in SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", item 15.e.i–v.
+					 *
+					 * The corresponding XML Schema lexical formats (e.g., "2023-05-19", "14:30:00Z",
+					 * "2023-05-19T14:30:00+01:00") follow ISO 8601 and are specified in
+					 * W3C XML Schema Part 2: Primitive Datatypes §3.2.7 (dateTime) and §3.2.9 (date).
+					 */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/*
+					 * SQL interval types must be mapped to XML Schema types when casting to XML:
+					 *   - Year-month intervals → xs:yearMonthDuration
+					 *   - Day-time intervals   → xs:dayTimeDuration
+					 *
+					 * This behavior is required by SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii.1–2.
+					 *
+					 * These XML Schema types require ISO 8601-compatible lexical representations,
+					 * such as: "P1Y2M", "P3DT4H5M", or "P1Y2M3DT4H5M6S", as defined in
+					 * W3C XML Schema Part 2: Primitve Datatypes, §3.2.6 (duration)
+					 */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				case INT2OID:
+				case INT4OID:
+				case INT8OID:
+				case NUMERICOID:
+				case FLOAT4OID:
+				case FLOAT8OID:
+				case BOOLOID:
+				case TIMESTAMPOID:
+				case TIMESTAMPTZOID:
+				case TIMEOID:
+				case TIMETZOID:
+				case DATEOID:
+				case BYTEAOID:
+				case INTERVALOID:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				default:
+					elog(ERROR, "unsupported target data type for XMLCast");
+				}
+
+				*op->resnull = false;
+			}
 			break;
-	}
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
+			}
 }
 
 /*
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index ede838cd40..8994bdda8e 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1732,6 +1732,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4464,6 +4467,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index a4b29c822e..8a599f9641 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -794,7 +794,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16144,6 +16144,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18195,6 +18213,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18783,6 +18802,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 12119f147f..34a2925e0e 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,37 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+/*
+ * Determines whether a type category is allowed in XMLCAST conversions,
+ * either as a source (SQL -> XML) or target (XML -> SQL) type.
+ *
+ * Based on SQL/XML:2023 (ISO/IEC 9075-14:2023),
+ * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii:
+ *
+ * - Items 1–2 explicitly describe interval mappings:
+ *     1) Year-month intervals -> xs:yearMonthDuration
+ *     2) Day-time intervals   -> xs:dayTimeDuration
+ *
+ * - Items 3–4 describe the general case:
+ *     3) If the target XML type is an XML Schema built-in data type,
+ *     or
+ *     4) If it is derived from a built-in atomic type,
+ *     then that type (or its base type) governs the conversion.
+ *
+ * These built-in and atomic types are defined in "W3C XML Schema Part 2:
+ * Datatypes", and include types such as xs:boolean, xs:decimal, xs:date,
+ * xs:dateTime, and xs:string. While SQL/XML does not enumerate mappings
+ * for all these types, it relies on their existence and semantics to
+ * support conversions.
+ *
+ * As such, PostgreSQL allows casting to and from types in the following
+ * categories: numeric, string, datetime, boolean, and timespan.
+ */
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC \
+			|| (x) == TYPCATEGORY_STRING || (x) == TYPCATEGORY_DATETIME \
+			|| (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +98,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -275,6 +307,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2467,6 +2503,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2483,6 +2523,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	/*
+	 * Ensure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * It is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as text and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 905c975d83..4b2fee64cb 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1955,6 +1955,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1981,6 +1984,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 79ec136231..c708be1ebd 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10115,6 +10115,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10125,7 +10128,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10161,6 +10164,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10238,6 +10242,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 35c915573a..d9eae5ed4f 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2762,6 +2762,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index ecbddd12e1..4da08cd152 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -877,6 +877,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1b4436f2ff..77c1be8ff0 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1602,6 +1602,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1638,6 +1639,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 84182eaaae..25306eddf0 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -508,6 +508,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 732dac47bc..7be87e3671 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..fd026305b7 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..40d642d59d 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..8c5488b9b8 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..1fae5b4b00 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 018b5919cf..a93b269af1 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3383,6 +3383,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.43.0

From d5e9c5afbae9243b8c0bb042fda6ef41a6c70f4f Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Thu, 6 Nov 2025 17:30:04 +0100
Subject: [PATCH v14] Add XMLCast function (SQL/XML X025)

This patch introduces support for the XMLCAST function, as specified
in SQL/XML:2023 (ISO/IEC 9075-14:2023), Subclause 6.7 "<XML cast
specification>". It enables standards-compliant conversion between
SQL data types and XML, following the lexical rules defined by the
W3C XML Schema Part 2.

XMLCast provides an alternative to CAST when converting SQL values
into XML content, ensuring the output uses canonical XML Schema
lexical representations. For example, timestamp and interval values
are rendered as `xs:dateTime` and `xs:duration` (e.g.,
"2024-01-01T12:00:00Z" or "P1Y2M"), conforming to ISO 8601 formats.

Conversely, XMLCast also allows converting XML content back into SQL
types (e.g., boolean, numeric, date/time), validating the input string
according to XML Schema lexical forms.

Supported casts include:
  - SQL -> XML: boolean, numeric, character, date/time, interval
  - XML -> SQL: the inverse of the above, with lexical validation

The BY REF and BY VALUE clauses are accepted for SQL/XML compatibility,
but ignored.

Documentation and regression tests are included.
---
 doc/src/sgml/datatype.sgml            |  87 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c | 123 +++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       | 108 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           |  61 +++
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 565 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 429 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 567 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 278 +++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 18 files changed, 2276 insertions(+), 10 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 1f2829e56a..12b66da7a4 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4494,14 +4494,93 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option for converting values to or from <type>xml</type> is the <function>xmlcast</function> function,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa, in a standards-compliant way.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. It is primarily used for converting between SQL values
+    and <type>xml</type> values in a standards-compliant way.
+
+    Unlike <function>CAST</function>, which may coerce SQL values into text or XML without enforcing a specific
+    lexical representation, <function>xmlcast</function> ensures that the conversion produces or expects a
+    canonical XML Schema lexical form appropriate for the target type. For example, an <type>interval</type>
+    value is rendered as <literal>P1Y2M</literal> (<type>xs:duration</type>), and a <type>timestamp</type> as
+    <literal>2023-05-19T14:30:00Z</literal> (xs:dateTime). Similarly, when converting from XML to SQL types,
+    <function>xmlcast</function> validates that the input string conforms to the lexical format required by the
+    corresponding SQL type.
+
+    The function <function>xmlcast</function> follows these rules:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <type>xml</type>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <type>xml</type> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>
+          values containing XML predefined entities will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Values of type <type>date</type>, <type>time with time zone</type>, <type>timestamp with time zone</type>,
+          and <type>interval</type> are converted to their corresponding XML Schema types: <type>xs:date</type>,
+          <type>xs:time</type>, <type>xs:dateTime</type>, and <type>xs:duration</type>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 3a8ad20160..412e1a4e37 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 0e1a74976f..246abaf544 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,11 +4644,127 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/*
+					 * SQL date/time types must be mapped to XML Schema types when casting to XML:
+					 *   - DATE                        -> xs:date
+					 *   - TIME [WITH/WITHOUT TZ]      -> xs:time
+					 *   - TIMESTAMP [WITH/WITHOUT TZ] -> xs:dateTime
+					 *
+					 * These mappings are defined in SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", item 15.e.i–v.
+					 *
+					 * The corresponding XML Schema lexical formats (e.g., "2023-05-19", "14:30:00Z",
+					 * "2023-05-19T14:30:00+01:00") follow ISO 8601 and are specified in
+					 * W3C XML Schema Part 2: Primitive Datatypes §3.2.7 (dateTime) and §3.2.9 (date).
+					 */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID)
+					{
+						text *mapped_value = cstring_to_text(
+							map_sql_value_to_xml_value(value, xexpr->type, false));
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/*
+					 * SQL interval types must be mapped to XML Schema types when casting to XML:
+					 *   - Year-month intervals → xs:yearMonthDuration
+					 *   - Day-time intervals   → xs:dayTimeDuration
+					 *
+					 * This behavior is required by SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii.1–2.
+					 *
+					 * These XML Schema types require ISO 8601-compatible lexical representations,
+					 * such as: "P1Y2M", "P3DT4H5M", or "P1Y2M3DT4H5M6S", as defined in
+					 * W3C XML Schema Part 2: Primitve Datatypes, §3.2.6 (duration)
+					 */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					*op->resvalue = PointerGetDatum(
+						cstring_to_text(unescape_xml(str)));
+
+					pfree(str);
+					break;
+				case INT2OID:
+				case INT4OID:
+				case INT8OID:
+				case NUMERICOID:
+				case FLOAT4OID:
+				case FLOAT8OID:
+				case BOOLOID:
+				case TIMESTAMPOID:
+				case TIMESTAMPTZOID:
+				case TIMEOID:
+				case TIMETZOID:
+				case DATEOID:
+				case BYTEAOID:
+				case INTERVALOID:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				default:
+					elog(ERROR, "unsupported target data type for XMLCast");
+				}
+
+				*op->resnull = false;
+			}
 			break;
-	}
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
+			}
 }
 
 /*
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index ede838cd40..8994bdda8e 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1732,6 +1732,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4464,6 +4467,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 57fe018654..86c9a2b11d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -794,7 +794,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WAIT WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16165,6 +16165,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18238,6 +18256,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18828,6 +18847,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 32d6ae918c..b61e24ad54 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,37 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+/*
+ * Determines whether a type category is allowed in XMLCAST conversions,
+ * either as a source (SQL -> XML) or target (XML -> SQL) type.
+ *
+ * Based on SQL/XML:2023 (ISO/IEC 9075-14:2023),
+ * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii:
+ *
+ * - Items 1–2 explicitly describe interval mappings:
+ *     1) Year-month intervals -> xs:yearMonthDuration
+ *     2) Day-time intervals   -> xs:dayTimeDuration
+ *
+ * - Items 3–4 describe the general case:
+ *     3) If the target XML type is an XML Schema built-in data type,
+ *     or
+ *     4) If it is derived from a built-in atomic type,
+ *     then that type (or its base type) governs the conversion.
+ *
+ * These built-in and atomic types are defined in "W3C XML Schema Part 2:
+ * Datatypes", and include types such as xs:boolean, xs:decimal, xs:date,
+ * xs:dateTime, and xs:string. While SQL/XML does not enumerate mappings
+ * for all these types, it relies on their existence and semantics to
+ * support conversions.
+ *
+ * As such, PostgreSQL allows casting to and from types in the following
+ * categories: numeric, string, datetime, boolean, and timespan.
+ */
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC \
+			|| (x) == TYPCATEGORY_STRING || (x) == TYPCATEGORY_DATETIME \
+			|| (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +98,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -275,6 +307,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2467,6 +2503,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2483,6 +2523,74 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	/*
+	 * Ensure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * It is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as text and later on return them as XML.
+	 */
+	if (inputTypcategory == TYPCATEGORY_NUMERIC || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 905c975d83..4b2fee64cb 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1955,6 +1955,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1981,6 +1984,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 556ab057e5..b69ad29caf 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10119,6 +10119,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10129,7 +10132,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10165,6 +10168,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10242,6 +10246,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 41e775570e..af7b20938a 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -2762,6 +2762,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d14294a4ec..c9d097e097 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -877,6 +877,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1b4436f2ff..77c1be8ff0 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1602,6 +1602,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1638,6 +1639,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 5d4fe27ef9..42f98cb7b2 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -510,6 +510,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 732dac47bc..7be87e3671 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..fd026305b7 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,568 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..40d642d59d 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,432 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..8c5488b9b8 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,570 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910::text AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision::text AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..1fae5b4b00 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,281 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 432509277c..5248283a05 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3390,6 +3390,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.43.0

From 2fead54c86ba1fcc4db25b2f207eea86035bf80e Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Fri, 28 Nov 2025 11:11:19 +0100
Subject: [PATCH v15] Add XMLCast function (SQL/XML X025)

This patch introduces support for the XMLCAST function, as specified
in SQL/XML:2023 (ISO/IEC 9075-14:2023), Subclause 6.7 "<XML cast
specification>". It enables standards-compliant conversion between
SQL data types and XML, following the lexical rules defined by the
W3C XML Schema Part 2.

XMLCast provides an alternative to CAST when converting SQL values
into XML content, ensuring the output uses canonical XML Schema
lexical representations. For example, timestamp and interval values
are rendered as xs:dateTime and xs:duration (e.g.,
"2024-01-01T12:00:00Z" or "P1Y2M"), conforming to ISO 8601 formats.

Conversely, XMLCast also allows converting XML content back into SQL
types (e.g., boolean, numeric, date/time), validating the input string
according to XML Schema lexical forms.

Supported casts include:
  - SQL -> XML: boolean, numeric, character, date/time, interval
  - XML -> SQL: the inverse of the above, with lexical validation

The BY REF and BY VALUE clauses are accepted for SQL/XML compatibility,
but ignored.

To support proper handling of infinity values in numeric types during
XML casting (as required by XML Schema specifications), two helper
functions (numeric_is_inf and numeric_is_positive_inf) have been
added to numeric.c.
---
 doc/src/sgml/datatype.sgml            |  87 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c | 135 +++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       | 109 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/numeric.c       |  22 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           | 121 ++++-
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/numeric.h           |   2 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 607 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 453 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 609 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 290 ++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 20 files changed, 2490 insertions(+), 13 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 1f2829e56a..12b66da7a4 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4494,14 +4494,93 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option for converting values to or from <type>xml</type> is the <function>xmlcast</function> function,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa, in a standards-compliant way.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. It is primarily used for converting between SQL values
+    and <type>xml</type> values in a standards-compliant way.
+
+    Unlike <function>CAST</function>, which may coerce SQL values into text or XML without enforcing a specific
+    lexical representation, <function>xmlcast</function> ensures that the conversion produces or expects a
+    canonical XML Schema lexical form appropriate for the target type. For example, an <type>interval</type>
+    value is rendered as <literal>P1Y2M</literal> (<type>xs:duration</type>), and a <type>timestamp</type> as
+    <literal>2023-05-19T14:30:00Z</literal> (xs:dateTime). Similarly, when converting from XML to SQL types,
+    <function>xmlcast</function> validates that the input string conforms to the lexical format required by the
+    corresponding SQL type.
+
+    The function <function>xmlcast</function> follows these rules:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <type>xml</type>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <type>xml</type> and character, numeric, date/time, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>
+          values containing XML predefined entities will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Values of type <type>date</type>, <type>time with time zone</type>, <type>timestamp with time zone</type>,
+          and <type>interval</type> are converted to their corresponding XML Schema types: <type>xs:date</type>,
+          <type>xs:time</type>, <type>xs:dateTime</type>, and <type>xs:duration</type>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 3a8ad20160..412e1a4e37 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 0e1a74976f..a21750e8c9 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,11 +4644,139 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/*
+					 * Certain SQL data types must be mapped to XML Schema types when casting to XML:
+					 *   - DATE                        -> xs:date
+					 *   - TIME [WITH/WITHOUT TZ]      -> xs:time
+					 *   - TIMESTAMP [WITH/WITHOUT TZ] -> xs:dateTime
+					 *   - BOOLEAN                     -> xs:boolean ("true"/"false")
+					 *   - BYTEA                       -> xs:base64Binary or xs:hexBinary
+					 *   - FLOAT/DOUBLE/NUMERIC        -> xs:float/double/decimal (with INF/-INF handling)
+					 *
+					 * These mappings are defined in SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", Syntax Rules, item 15.e.i–v.
+					 *
+					 * The corresponding XML Schema lexical formats follow ISO 8601 and are specified in
+					 * W3C XML Schema Part 2: Primitive Datatypes:
+					 *   - §3.2.7 (dateTime): "2023-05-19T14:30:00+01:00"
+					 *   - §3.2.8 (time): "14:30:00Z"
+					 *   - §3.2.9 (date): "2023-05-19"
+					 *   - §3.2.2 (boolean): "true"/"false"
+					 *   - §3.2.16 (base64Binary/hexBinary): base64/hex encoded strings
+					 *   - §3.2.4 (float) and §3.2.5 (double): with "INF"/"-INF" for infinity
+					 */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID ||
+						xexpr->type == FLOAT4OID || xexpr->type == FLOAT8OID || xexpr->type == NUMERICOID)
+					{
+						char *strdt = map_sql_value_to_xml_value(value, xexpr->type, false);
+						text *mapped_value = cstring_to_text(strdt);
+						pfree(strdt);
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/*
+					 * SQL interval types must be mapped to XML Schema types when casting to XML:
+					 *   - Year-month intervals → xs:yearMonthDuration
+					 *   - Day-time intervals   → xs:dayTimeDuration
+					 *
+					 * This behavior is required by SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii.1–2.
+					 *
+					 * These XML Schema types require ISO 8601-compatible lexical representations,
+					 * such as: "P1Y2M", "P3DT4H5M", or "P1Y2M3DT4H5M6S", as defined in
+					 * W3C XML Schema Part 2: Primitive Datatypes, §3.2.6 (duration)
+					 */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					{
+						char *unescaped = unescape_xml(str);
+						*op->resvalue = PointerGetDatum(cstring_to_text(unescaped));
+						pfree(unescaped);
+					}
+					pfree(str);
+					break;
+				case INT2OID:
+				case INT4OID:
+				case INT8OID:
+				case NUMERICOID:
+				case FLOAT4OID:
+				case FLOAT8OID:
+				case BOOLOID:
+				case TIMESTAMPOID:
+				case TIMESTAMPTZOID:
+				case TIMEOID:
+				case TIMETZOID:
+				case DATEOID:
+				case BYTEAOID:
+				case INTERVALOID:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				default:
+					elog(ERROR, "unsupported target data type for XMLCast");
+				}
+
+				*op->resnull = false;
+			}
 			break;
-	}
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
+			}
 }
 
 /*
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d228318dc7..0e4f0cdc51 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1732,6 +1732,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4464,6 +4467,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c3a0a354a9..a615a7b1ba 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -794,7 +794,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WAIT WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16164,6 +16164,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18237,6 +18255,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18827,6 +18846,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 44fd1385f8..b7f9ba4abb 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,37 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+/*
+ * Determines whether a type category is allowed in XMLCAST conversions,
+ * either as a source (SQL -> XML) or target (XML -> SQL) type.
+ *
+ * Based on SQL/XML:2023 (ISO/IEC 9075-14:2023),
+ * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii:
+ *
+ * - Items 1–2 explicitly describe interval mappings:
+ *     1) Year-month intervals -> xs:yearMonthDuration
+ *     2) Day-time intervals   -> xs:dayTimeDuration
+ *
+ * - Items 3–4 describe the general case:
+ *     3) If the target XML type is an XML Schema built-in data type,
+ *     or
+ *     4) If it is derived from a built-in atomic type,
+ *     then that type (or its base type) governs the conversion.
+ *
+ * These built-in and atomic types are defined in "W3C XML Schema Part 2:
+ * Datatypes", and include types such as xs:boolean, xs:decimal, xs:date,
+ * xs:dateTime, and xs:string. While SQL/XML does not enumerate mappings
+ * for all these types, it relies on their existence and semantics to
+ * support conversions.
+ *
+ * As such, PostgreSQL allows casting to and from types in the following
+ * categories: numeric, string, datetime, boolean, and timespan.
+ */
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC \
+			|| (x) == TYPCATEGORY_STRING || (x) == TYPCATEGORY_DATETIME \
+			|| (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +98,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -275,6 +307,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2467,6 +2503,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2483,6 +2523,75 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	/*
+	 * Ensure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * It is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as text and later on return them as XML.
+	 */
+	if ((inputTypcategory == TYPCATEGORY_NUMERIC && inputType != FLOAT4OID &&
+		inputType != FLOAT8OID && inputType != NUMERICOID) || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 905c975d83..4b2fee64cb 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1955,6 +1955,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1981,6 +1984,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 2501007d98..2278d8154e 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -847,6 +847,28 @@ numeric_is_inf(Numeric num)
 	return NUMERIC_IS_INF(num);
 }
 
+/*
+ * numeric_is_positive_inf() -
+ *
+ *	Is Numeric value positive infinity?
+ */
+bool
+numeric_is_positive_inf(Numeric num)
+{
+	return NUMERIC_IS_PINF(num);
+}
+
+/*
+ * numeric_is_negative_inf() -
+ *
+ *	Is Numeric value negative infinity?
+ */
+bool
+numeric_is_negative_inf(Numeric num)
+{
+	return NUMERIC_IS_NINF(num);
+}
+
 /*
  * numeric_is_integral() -
  *
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 556ab057e5..b69ad29caf 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10119,6 +10119,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10129,7 +10132,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10165,6 +10168,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10242,6 +10246,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 41e775570e..4285164891 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -99,6 +99,7 @@
 #include "utils/date.h"
 #include "utils/datetime.h"
 #include "utils/lsyscache.h"
+#include "utils/numeric.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/xml.h"
@@ -2574,9 +2575,9 @@ map_sql_value_to_xml_value(Datum value, Oid type, bool xml_escape_strings)
 		{
 			case BOOLOID:
 				if (DatumGetBool(value))
-					return "true";
+					return pstrdup("true");
 				else
-					return "false";
+					return pstrdup("false");
 
 			case DATEOID:
 				{
@@ -2706,8 +2707,60 @@ map_sql_value_to_xml_value(Datum value, Oid type, bool xml_escape_strings)
 				}
 #endif							/* USE_LIBXML */
 
-		}
+			case FLOAT4OID:
+				/*
+				 * Special handling for infinity values in floating-point and
+				 * numeric types. The XML Schema specification requires that
+				 * positive infinity be represented as "INF" and negative
+				 * infinity as "-INF" in XML documents for float and double
+				 * types. While decimal types in XML Schema do not support
+				 * infinity, PostgreSQL's NUMERIC type can represent it, so
+				 * we use the same representation for consistency.
+				 *
+				 * See: XML Schema Part 2: Datatypes Second Edition, sections
+				 * 3.2.4 (float) and 3.2.5 (double).
+				 */
+				{
+					float4		val = DatumGetFloat4(value);
+
+					if (isinf(val))
+					{
+						if (val < 0)
+							return pstrdup("-INF");
+						else
+							return pstrdup("INF");
+					}
+				}
+				break;
 
+			case FLOAT8OID:
+				{
+					float8		val = DatumGetFloat8(value);
+
+					if (isinf(val))
+					{
+						if (val < 0)
+							return pstrdup("-INF");
+						else
+							return pstrdup("INF");
+					}
+				}
+				break;
+
+			case NUMERICOID:
+				{
+					Numeric		num = DatumGetNumeric(value);
+
+					if (numeric_is_inf(num))
+					{
+						if (numeric_is_positive_inf(num))
+							return pstrdup("INF");
+						else
+							return pstrdup("-INF");
+					}
+				}
+				break;
+		}
 		/*
 		 * otherwise, just use the type's native text representation
 		 */
@@ -2762,6 +2815,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
@@ -4350,6 +4464,7 @@ xml_xpathobjtoxmlarray(xmlXPathObjectPtr xpathobj,
 	datum = PointerGetDatum(cstring_to_xmltype(result_str));
 	(void) accumArrayResult(astate, datum, false,
 							XMLOID, CurrentMemoryContext);
+	pfree(result_str);
 	return 1;
 }
 
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d14294a4ec..c9d097e097 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -877,6 +877,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1b4436f2ff..77c1be8ff0 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1602,6 +1602,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1638,6 +1639,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 5d4fe27ef9..42f98cb7b2 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -510,6 +510,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/numeric.h b/src/include/utils/numeric.h
index 215f1ea4f5..c57432507e 100644
--- a/src/include/utils/numeric.h
+++ b/src/include/utils/numeric.h
@@ -87,6 +87,8 @@ NumericGetDatum(Numeric X)
  */
 extern bool numeric_is_nan(Numeric num);
 extern bool numeric_is_inf(Numeric num);
+extern bool numeric_is_positive_inf(Numeric num);
+extern bool numeric_is_negative_inf(Numeric num);
 extern int32 numeric_maximum_size(int32 typmod);
 extern char *numeric_out_sci(Numeric num, int scale);
 extern char *numeric_normalize(Numeric num);
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 732dac47bc..7be87e3671 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..a5a56c5b74 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,610 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof | xmlcast  | pg_typeof |  xmlcast  | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------+----------+-----------+-----------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric   | Infinity | numeric   | -Infinity | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     | xmlcast  |    pg_typeof     |  xmlcast  |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------+----------+------------------+-----------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision | Infinity | double precision | -Infinity | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910 AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..98b2a2878e 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,456 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..5ec57ae5ef 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,612 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof | xmlcast  | pg_typeof |  xmlcast  | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------+----------+-----------+-----------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric   | Infinity | numeric   | -Infinity | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     | xmlcast  |    pg_typeof     |  xmlcast  |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------+----------+------------------+-----------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision | Infinity | double precision | -Infinity | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910 AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..648751d212 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,293 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index e3c3523b5b..a33bda3416 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3400,6 +3400,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.43.0

From 3ae6f83162d4f1c9aecba1f37946c4cda86e2ac7 Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Fri, 28 Nov 2025 11:11:19 +0100
Subject: [PATCH v16] Add XMLCast function (SQL/XML X025)

This patch introduces support for the XMLCAST function, as specified
in SQL/XML:2023 (ISO/IEC 9075-14:2023), Subclause 6.7 "<XML cast
specification>". It enables standards-compliant conversion between
SQL data types and XML, following the lexical rules defined by the
W3C XML Schema Part 2.

XMLCast provides an alternative to CAST when converting SQL values
into XML content, ensuring the output uses canonical XML Schema
lexical representations. For example, timestamp and interval values
are rendered as xs:dateTime and xs:duration (e.g.,
"2024-01-01T12:00:00Z" or "P1Y2M"), conforming to ISO 8601 formats.

Conversely, XMLCast also allows converting XML content back into SQL
types (e.g., boolean, numeric, date/time), validating the input string
according to XML Schema lexical forms.

Supported casts include:
* SQL -> XML: boolean, numeric, character, date/time, interval, binary
* XML -> SQL: the inverse of the above, with lexical validation

The BY REF and BY VALUE clauses are accepted for SQL/XML compatibility,
but ignored.

To support proper handling of infinity values in numeric types during
XML casting (as required by XML Schema specifications), two helper
functions (numeric_is_inf and numeric_is_positive_inf) have been
added to numeric.c.
---
 doc/src/sgml/datatype.sgml            |  87 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c | 135 +++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       | 109 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/numeric.c       |  22 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           | 121 ++++-
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/numeric.h           |   2 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 607 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 453 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 609 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 290 ++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 20 files changed, 2490 insertions(+), 13 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 1f2829e56a..153e71b7e8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4494,14 +4494,93 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option for converting values to or from <type>xml</type> is the <function>xmlcast</function> function,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa, in a standards-compliant way.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. It is primarily used for converting between SQL values
+    and <type>xml</type> values in a standards-compliant way.
+
+    Unlike <function>CAST</function>, which may coerce SQL values into text or XML without enforcing a specific
+    lexical representation, <function>xmlcast</function> ensures that the conversion produces or expects a
+    canonical XML Schema lexical form appropriate for the target type. For example, an <type>interval</type>
+    value is rendered as <literal>P1Y2M</literal> (<type>xs:duration</type>), and a <type>timestamp</type> as
+    <literal>2023-05-19T14:30:00Z</literal> (xs:dateTime). Similarly, when converting from XML to SQL types,
+    <function>xmlcast</function> validates that the input string conforms to the lexical format required by the
+    corresponding SQL type.
+
+    The function <function>xmlcast</function> follows these rules:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <type>xml</type>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          It supports casting between <type>xml</type> and character, numeric, date/time, binary, and boolean data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>
+          values containing XML predefined entities will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Values of type <type>date</type>, <type>time with time zone</type>, <type>timestamp with time zone</type>,
+          and <type>interval</type> are converted to their corresponding XML Schema types: <type>xs:date</type>,
+          <type>xs:time</type>, <type>xs:dateTime</type>, and <type>xs:duration</type>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 3a8ad20160..412e1a4e37 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 0e1a74976f..a21750e8c9 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,11 +4644,139 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/*
+					 * Certain SQL data types must be mapped to XML Schema types when casting to XML:
+					 *   - DATE                        -> xs:date
+					 *   - TIME [WITH/WITHOUT TZ]      -> xs:time
+					 *   - TIMESTAMP [WITH/WITHOUT TZ] -> xs:dateTime
+					 *   - BOOLEAN                     -> xs:boolean ("true"/"false")
+					 *   - BYTEA                       -> xs:base64Binary or xs:hexBinary
+					 *   - FLOAT/DOUBLE/NUMERIC        -> xs:float/double/decimal (with INF/-INF handling)
+					 *
+					 * These mappings are defined in SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", Syntax Rules, item 15.e.i–v.
+					 *
+					 * The corresponding XML Schema lexical formats follow ISO 8601 and are specified in
+					 * W3C XML Schema Part 2: Primitive Datatypes:
+					 *   - §3.2.7 (dateTime): "2023-05-19T14:30:00+01:00"
+					 *   - §3.2.8 (time): "14:30:00Z"
+					 *   - §3.2.9 (date): "2023-05-19"
+					 *   - §3.2.2 (boolean): "true"/"false"
+					 *   - §3.2.16 (base64Binary/hexBinary): base64/hex encoded strings
+					 *   - §3.2.4 (float) and §3.2.5 (double): with "INF"/"-INF" for infinity
+					 */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID ||
+						xexpr->type == FLOAT4OID || xexpr->type == FLOAT8OID || xexpr->type == NUMERICOID)
+					{
+						char *strdt = map_sql_value_to_xml_value(value, xexpr->type, false);
+						text *mapped_value = cstring_to_text(strdt);
+						pfree(strdt);
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/*
+					 * SQL interval types must be mapped to XML Schema types when casting to XML:
+					 *   - Year-month intervals → xs:yearMonthDuration
+					 *   - Day-time intervals   → xs:dayTimeDuration
+					 *
+					 * This behavior is required by SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii.1–2.
+					 *
+					 * These XML Schema types require ISO 8601-compatible lexical representations,
+					 * such as: "P1Y2M", "P3DT4H5M", or "P1Y2M3DT4H5M6S", as defined in
+					 * W3C XML Schema Part 2: Primitive Datatypes, §3.2.6 (duration)
+					 */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					{
+						char *unescaped = unescape_xml(str);
+						*op->resvalue = PointerGetDatum(cstring_to_text(unescaped));
+						pfree(unescaped);
+					}
+					pfree(str);
+					break;
+				case INT2OID:
+				case INT4OID:
+				case INT8OID:
+				case NUMERICOID:
+				case FLOAT4OID:
+				case FLOAT8OID:
+				case BOOLOID:
+				case TIMESTAMPOID:
+				case TIMESTAMPTZOID:
+				case TIMEOID:
+				case TIMETZOID:
+				case DATEOID:
+				case BYTEAOID:
+				case INTERVALOID:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				default:
+					elog(ERROR, "unsupported target data type for XMLCast");
+				}
+
+				*op->resnull = false;
+			}
 			break;
-	}
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
+			}
 }
 
 /*
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d228318dc7..0e4f0cdc51 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1732,6 +1732,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4464,6 +4467,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c3a0a354a9..a615a7b1ba 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -794,7 +794,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WAIT WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16164,6 +16164,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18237,6 +18255,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18827,6 +18846,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 44fd1385f8..b7f9ba4abb 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,37 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+/*
+ * Determines whether a type category is allowed in XMLCAST conversions,
+ * either as a source (SQL -> XML) or target (XML -> SQL) type.
+ *
+ * Based on SQL/XML:2023 (ISO/IEC 9075-14:2023),
+ * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii:
+ *
+ * - Items 1–2 explicitly describe interval mappings:
+ *     1) Year-month intervals -> xs:yearMonthDuration
+ *     2) Day-time intervals   -> xs:dayTimeDuration
+ *
+ * - Items 3–4 describe the general case:
+ *     3) If the target XML type is an XML Schema built-in data type,
+ *     or
+ *     4) If it is derived from a built-in atomic type,
+ *     then that type (or its base type) governs the conversion.
+ *
+ * These built-in and atomic types are defined in "W3C XML Schema Part 2:
+ * Datatypes", and include types such as xs:boolean, xs:decimal, xs:date,
+ * xs:dateTime, and xs:string. While SQL/XML does not enumerate mappings
+ * for all these types, it relies on their existence and semantics to
+ * support conversions.
+ *
+ * As such, PostgreSQL allows casting to and from types in the following
+ * categories: numeric, string, datetime, boolean, and timespan.
+ */
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC \
+			|| (x) == TYPCATEGORY_STRING || (x) == TYPCATEGORY_DATETIME \
+			|| (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +98,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -275,6 +307,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2467,6 +2503,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2483,6 +2523,75 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	/*
+	 * Ensure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * It is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as text and later on return them as XML.
+	 */
+	if ((inputTypcategory == TYPCATEGORY_NUMERIC && inputType != FLOAT4OID &&
+		inputType != FLOAT8OID && inputType != NUMERICOID) || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 905c975d83..4b2fee64cb 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1955,6 +1955,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1981,6 +1984,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 2501007d98..2278d8154e 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -847,6 +847,28 @@ numeric_is_inf(Numeric num)
 	return NUMERIC_IS_INF(num);
 }
 
+/*
+ * numeric_is_positive_inf() -
+ *
+ *	Is Numeric value positive infinity?
+ */
+bool
+numeric_is_positive_inf(Numeric num)
+{
+	return NUMERIC_IS_PINF(num);
+}
+
+/*
+ * numeric_is_negative_inf() -
+ *
+ *	Is Numeric value negative infinity?
+ */
+bool
+numeric_is_negative_inf(Numeric num)
+{
+	return NUMERIC_IS_NINF(num);
+}
+
 /*
  * numeric_is_integral() -
  *
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 556ab057e5..b69ad29caf 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10119,6 +10119,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10129,7 +10132,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10165,6 +10168,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10242,6 +10246,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 41e775570e..4285164891 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -99,6 +99,7 @@
 #include "utils/date.h"
 #include "utils/datetime.h"
 #include "utils/lsyscache.h"
+#include "utils/numeric.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/xml.h"
@@ -2574,9 +2575,9 @@ map_sql_value_to_xml_value(Datum value, Oid type, bool xml_escape_strings)
 		{
 			case BOOLOID:
 				if (DatumGetBool(value))
-					return "true";
+					return pstrdup("true");
 				else
-					return "false";
+					return pstrdup("false");
 
 			case DATEOID:
 				{
@@ -2706,8 +2707,60 @@ map_sql_value_to_xml_value(Datum value, Oid type, bool xml_escape_strings)
 				}
 #endif							/* USE_LIBXML */
 
-		}
+			case FLOAT4OID:
+				/*
+				 * Special handling for infinity values in floating-point and
+				 * numeric types. The XML Schema specification requires that
+				 * positive infinity be represented as "INF" and negative
+				 * infinity as "-INF" in XML documents for float and double
+				 * types. While decimal types in XML Schema do not support
+				 * infinity, PostgreSQL's NUMERIC type can represent it, so
+				 * we use the same representation for consistency.
+				 *
+				 * See: XML Schema Part 2: Datatypes Second Edition, sections
+				 * 3.2.4 (float) and 3.2.5 (double).
+				 */
+				{
+					float4		val = DatumGetFloat4(value);
+
+					if (isinf(val))
+					{
+						if (val < 0)
+							return pstrdup("-INF");
+						else
+							return pstrdup("INF");
+					}
+				}
+				break;
 
+			case FLOAT8OID:
+				{
+					float8		val = DatumGetFloat8(value);
+
+					if (isinf(val))
+					{
+						if (val < 0)
+							return pstrdup("-INF");
+						else
+							return pstrdup("INF");
+					}
+				}
+				break;
+
+			case NUMERICOID:
+				{
+					Numeric		num = DatumGetNumeric(value);
+
+					if (numeric_is_inf(num))
+					{
+						if (numeric_is_positive_inf(num))
+							return pstrdup("INF");
+						else
+							return pstrdup("-INF");
+					}
+				}
+				break;
+		}
 		/*
 		 * otherwise, just use the type's native text representation
 		 */
@@ -2762,6 +2815,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
@@ -4350,6 +4464,7 @@ xml_xpathobjtoxmlarray(xmlXPathObjectPtr xpathobj,
 	datum = PointerGetDatum(cstring_to_xmltype(result_str));
 	(void) accumArrayResult(astate, datum, false,
 							XMLOID, CurrentMemoryContext);
+	pfree(result_str);
 	return 1;
 }
 
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d14294a4ec..c9d097e097 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -877,6 +877,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1b4436f2ff..77c1be8ff0 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1602,6 +1602,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1638,6 +1639,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 5d4fe27ef9..42f98cb7b2 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -510,6 +510,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/numeric.h b/src/include/utils/numeric.h
index 215f1ea4f5..c57432507e 100644
--- a/src/include/utils/numeric.h
+++ b/src/include/utils/numeric.h
@@ -87,6 +87,8 @@ NumericGetDatum(Numeric X)
  */
 extern bool numeric_is_nan(Numeric num);
 extern bool numeric_is_inf(Numeric num);
+extern bool numeric_is_positive_inf(Numeric num);
+extern bool numeric_is_negative_inf(Numeric num);
 extern int32 numeric_maximum_size(int32 typmod);
 extern char *numeric_out_sci(Numeric num, int scale);
 extern char *numeric_normalize(Numeric num);
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 732dac47bc..7be87e3671 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..a5a56c5b74 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,610 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof | xmlcast  | pg_typeof |  xmlcast  | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------+----------+-----------+-----------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric   | Infinity | numeric   | -Infinity | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     | xmlcast  |    pg_typeof     |  xmlcast  |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------+----------+------------------+-----------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision | Infinity | double precision | -Infinity | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910 AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..98b2a2878e 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,456 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..5ec57ae5ef 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,612 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof | xmlcast  | pg_typeof |  xmlcast  | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------+----------+-----------+-----------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric   | Infinity | numeric   | -Infinity | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     | xmlcast  |    pg_typeof     |  xmlcast  |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------+----------+------------------+-----------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision | Infinity | double precision | -Infinity | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910 AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..648751d212 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,293 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index e3c3523b5b..a33bda3416 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3400,6 +3400,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.43.0

From 9efe547245835011848506f07013a19396163fde Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Fri, 28 Nov 2025 11:11:19 +0100
Subject: [PATCH v17] Add XMLCast function (SQL/XML X025)

This patch introduces support for the XMLCAST function, as specified
in SQL/XML:2023 (ISO/IEC 9075-14:2023), Subclause 6.7 "<XML cast
specification>". It enables standards-compliant conversion between
SQL data types and XML, following the lexical rules defined by the
W3C XML Schema Part 2.

XMLCast provides an alternative to CAST when converting SQL values
into XML content, ensuring the output uses canonical XML Schema
lexical representations. For example, timestamp and interval values
are rendered as xs:dateTime and xs:duration (e.g.,
"2024-01-01T12:00:00Z" or "P1Y2M"), conforming to ISO 8601 formats.

Conversely, XMLCast also allows converting XML content back into SQL
types (e.g., boolean, numeric, date/time), validating the input string
according to XML Schema lexical forms.

Supported casts include:
* SQL -> XML: boolean, numeric, character, date/time, interval, binary
* XML -> SQL: the inverse of the above, with lexical validation

The BY REF and BY VALUE clauses are accepted for SQL/XML compatibility,
but ignored.

To support proper handling of infinity values in numeric types during
XML casting (as required by XML Schema specifications), two helper
functions (numeric_is_inf and numeric_is_positive_inf) have been
added to numeric.c.
---
 doc/src/sgml/datatype.sgml            |  89 +++-
 src/backend/catalog/sql_features.txt  |   2 +-
 src/backend/executor/execExprInterp.c | 135 +++++-
 src/backend/nodes/nodeFuncs.c         |  13 +
 src/backend/parser/gram.y             |  22 +-
 src/backend/parser/parse_expr.c       | 109 +++++
 src/backend/parser/parse_target.c     |   7 +
 src/backend/utils/adt/numeric.c       |  22 +
 src/backend/utils/adt/ruleutils.c     |  10 +-
 src/backend/utils/adt/xml.c           | 121 ++++-
 src/include/nodes/parsenodes.h        |   8 +
 src/include/nodes/primnodes.h         |   3 +
 src/include/parser/kwlist.h           |   1 +
 src/include/utils/numeric.h           |   2 +
 src/include/utils/xml.h               |   1 +
 src/test/regress/expected/xml.out     | 607 +++++++++++++++++++++++++
 src/test/regress/expected/xml_1.out   | 453 +++++++++++++++++++
 src/test/regress/expected/xml_2.out   | 609 ++++++++++++++++++++++++++
 src/test/regress/sql/xml.sql          | 290 ++++++++++++
 src/tools/pgindent/typedefs.list      |   1 +
 20 files changed, 2492 insertions(+), 13 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 1f2829e56a..df35424e7d 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -4494,14 +4494,95 @@ XMLPARSE ( { DOCUMENT | CONTENT } <replaceable>value</replaceable>)
 XMLPARSE (DOCUMENT '<?xml version="1.0"?><book><title>Manual</title><chapter>...</chapter></book>')
 XMLPARSE (CONTENT 'abc<foo>bar</foo><bar>foo</bar>')
 ]]></programlisting>
-    While this is the only way to convert character strings into XML
-    values according to the SQL standard, the PostgreSQL-specific
-    syntaxes:
+
+    Another option for converting values to or from <type>xml</type> is the <function>xmlcast</function> function,
+    which is designed to cast SQL data types into <type>xml</type>, and vice versa, in a standards-compliant way.
+<synopsis>
+XMLCAST ( <replaceable>expression</replaceable> AS <replaceable>type</replaceable> [ BY REF | BY VALUE ] )
+</synopsis>
+    Similar to the SQL function <function>CAST</function>, this function converts an <replaceable>expression</replaceable>
+    into the specified <replaceable>type</replaceable>. It is primarily used for converting between SQL values
+    and <type>xml</type> values in a standards-compliant way.
+
+    Unlike <function>CAST</function>, which may coerce SQL values into text or XML without enforcing a specific
+    lexical representation, <function>xmlcast</function> ensures that the conversion produces or expects a
+    canonical XML Schema lexical form appropriate for the target type. For example, an <type>interval</type>
+    value is rendered as <literal>P1Y2M</literal> (<type>xs:duration</type>), and a <type>timestamp</type> as
+    <literal>2023-05-19T14:30:00Z</literal> (xs:dateTime). Similarly, when converting from XML to SQL types,
+    <function>xmlcast</function> validates that the input string conforms to the lexical format required by the
+    corresponding SQL type.
+
+    The function <function>xmlcast</function> follows these rules:
+
+     <itemizedlist>
+      <listitem>
+        <para>
+          Either <replaceable>expression</replaceable> or <replaceable>type</replaceable> must be of type <type>xml</type>.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Casting is supported between <type>xml</type> and <link linkend="datatype-character-table">character</link>,
+          <link linkend="datatype-numeric">numeric</link>, <link linkend="datatype-datetime">date/time</link>,
+          <link linkend="datatype-boolean">boolean</link> and <link linkend="datatype-binary">binary</link> data types.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Similar to the function <function>xmltext</function>, <replaceable>expression</replaceable>
+          values containing XML predefined entities will be escaped (see examples below).
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          Values of type <type>date</type>, <type>time with time zone</type>, <type>timestamp with time zone</type>,
+          and <type>interval</type> are converted to their corresponding XML Schema types: <type>xs:date</type>,
+          <type>xs:time</type>, <type>xs:dateTime</type>, and <type>xs:duration</type>, respectively.
+        </para>
+      </listitem>
+       <listitem>
+        <para>
+          The <literal>BY REF</literal> and <literal>BY VALUE</literal> clauses
+          are accepted but ignored, as discussed in
+          <xref linkend="functions-xml-limits-postgresql"/>.
+        </para>
+      </listitem>
+    </itemizedlist>
+
+     Examples:
+<screen><![CDATA[
+SELECT xmlcast('<foo&bar>'::text AS xml);
+       xmlcast
+---------------------
+ &lt;foo&amp;bar&gt;
+
+SELECT xmlcast('&lt;foo&amp;bar&gt;'::xml AS text);
+  xmlcast
+-----------
+ <foo&bar>
+
+SELECT xmlcast(CURRENT_TIMESTAMP AS xml);
+             xmlcast
+---------------------------------
+ 2024-06-02T00:29:40.92397+02:00
+
+SELECT xmlcast('P1Y2M3W4DT5H6M7S'::xml AS interval);
+            xmlcast
+--------------------------------
+ 1 year 2 mons 25 days 05:06:07
+
+SELECT xmlcast('1 year 2 months 3 weeks 4 days 5 hours 6 minutes 7 seconds'::interval AS xml);
+     xmlcast
+-----------------
+ P1Y2M25DT5H6M7S
+]]></screen>
+
+    Alternatively, it is also possible to convert character strings into XML using PostgreSQL-specific cast syntaxes:
 <programlisting><![CDATA[
 xml '<foo>bar</foo>'
 '<foo>bar</foo>'::xml
 ]]></programlisting>
-    can also be used.
+
    </para>
 
    <para>
diff --git a/src/backend/catalog/sql_features.txt b/src/backend/catalog/sql_features.txt
index 3a8ad20160..412e1a4e37 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -624,7 +624,7 @@ X014	Attributes of XML type			YES
 X015	Fields of XML type			NO	
 X016	Persistent XML values			YES	
 X020	XMLConcat			YES	
-X025	XMLCast			NO	
+X025	XMLCast			YES	
 X030	XMLDocument			NO	
 X031	XMLElement			YES	
 X032	XMLForest			YES	
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 0e1a74976f..a21750e8c9 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -69,6 +69,7 @@
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
+#include "utils/datetime.h"
 #include "utils/datum.h"
 #include "utils/expandedrecord.h"
 #include "utils/json.h"
@@ -4643,11 +4644,139 @@ ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op)
 				*op->resnull = false;
 			}
 			break;
+			case IS_XMLCAST:
+			{
+				Datum *argvalue = op->d.xmlexpr.argvalue;
+				bool *argnull = op->d.xmlexpr.argnull;
+				char *str;
 
-		default:
-			elog(ERROR, "unrecognized XML operation");
+				Assert(list_length(xexpr->args) == 1);
+
+				if (argnull[0])
+					return;
+
+				value = argvalue[0];
+
+				switch (xexpr->targetType)
+				{
+				case XMLOID:
+					/*
+					 * Certain SQL data types must be mapped to XML Schema types when casting to XML:
+					 *   - DATE                        -> xs:date
+					 *   - TIME [WITH/WITHOUT TZ]      -> xs:time
+					 *   - TIMESTAMP [WITH/WITHOUT TZ] -> xs:dateTime
+					 *   - BOOLEAN                     -> xs:boolean ("true"/"false")
+					 *   - BYTEA                       -> xs:base64Binary or xs:hexBinary
+					 *   - FLOAT/DOUBLE/NUMERIC        -> xs:float/double/decimal (with INF/-INF handling)
+					 *
+					 * These mappings are defined in SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", Syntax Rules, item 15.e.i–v.
+					 *
+					 * The corresponding XML Schema lexical formats follow ISO 8601 and are specified in
+					 * W3C XML Schema Part 2: Primitive Datatypes:
+					 *   - §3.2.7 (dateTime): "2023-05-19T14:30:00+01:00"
+					 *   - §3.2.8 (time): "14:30:00Z"
+					 *   - §3.2.9 (date): "2023-05-19"
+					 *   - §3.2.2 (boolean): "true"/"false"
+					 *   - §3.2.16 (base64Binary/hexBinary): base64/hex encoded strings
+					 *   - §3.2.4 (float) and §3.2.5 (double): with "INF"/"-INF" for infinity
+					 */
+					if (xexpr->type == TIMESTAMPOID || xexpr->type == TIMESTAMPTZOID ||
+						xexpr->type == DATEOID || xexpr->type == BYTEAOID || xexpr->type == BOOLOID ||
+						xexpr->type == FLOAT4OID || xexpr->type == FLOAT8OID || xexpr->type == NUMERICOID)
+					{
+						char *strdt = map_sql_value_to_xml_value(value, xexpr->type, false);
+						text *mapped_value = cstring_to_text(strdt);
+						pfree(strdt);
+						*op->resvalue = PointerGetDatum(mapped_value);
+					}
+					/*
+					 * SQL interval types must be mapped to XML Schema types when casting to XML:
+					 *   - Year-month intervals → xs:yearMonthDuration
+					 *   - Day-time intervals   → xs:dayTimeDuration
+					 *
+					 * This behavior is required by SQL/XML:2023 (ISO/IEC 9075-14:2023),
+					 * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii.1–2.
+					 *
+					 * These XML Schema types require ISO 8601-compatible lexical representations,
+					 * such as: "P1Y2M", "P3DT4H5M", or "P1Y2M3DT4H5M6S", as defined in
+					 * W3C XML Schema Part 2: Primitive Datatypes, §3.2.6 (duration)
+					 */
+					else if (xexpr->type == INTERVALOID)
+					{
+						Interval *in = DatumGetIntervalP(value);
+
+						struct pg_itm tt, *itm = &tt;
+						char buf[MAXDATELEN + 1];
+
+						if (INTERVAL_NOT_FINITE(in))
+						{
+							if (INTERVAL_IS_NOBEGIN(in))
+								strcpy(buf, EARLY);
+							else if (INTERVAL_IS_NOEND(in))
+								strcpy(buf, LATE);
+							else
+								elog(ERROR, "invalid interval argument");
+						}
+						else
+						{
+							interval2itm(*in, itm);
+							EncodeInterval(itm, INTSTYLE_ISO_8601, buf);
+						}
+
+						*op->resvalue = PointerGetDatum(cstring_to_text(buf));
+					}
+					/* no need to escape the result, as the origin is also an XML */
+					else if (xexpr->type == XMLOID)
+						*op->resvalue = PointerGetDatum(DatumGetXmlP(value));
+					/* we  make sure that potential predifined entitties are escaped */
+					else
+						*op->resvalue = PointerGetDatum(
+							DatumGetXmlP((DirectFunctionCall1(xmltext, value))));
+					break;
+				case TEXTOID:
+				case VARCHAROID:
+				case NAMEOID:
+				case BPCHAROID:
+					/*
+					 * when casting from XML to a character string we make sure that
+					 * all escaped xml characters are unescaped.
+					 */
+					str = text_to_cstring(DatumGetTextPP(value));
+					{
+						char *unescaped = unescape_xml(str);
+						*op->resvalue = PointerGetDatum(cstring_to_text(unescaped));
+						pfree(unescaped);
+					}
+					pfree(str);
+					break;
+				case INT2OID:
+				case INT4OID:
+				case INT8OID:
+				case NUMERICOID:
+				case FLOAT4OID:
+				case FLOAT8OID:
+				case BOOLOID:
+				case TIMESTAMPOID:
+				case TIMESTAMPTZOID:
+				case TIMEOID:
+				case TIMETZOID:
+				case DATEOID:
+				case BYTEAOID:
+				case INTERVALOID:
+					*op->resvalue = PointerGetDatum(DatumGetTextP(value));
+					break;
+				default:
+					elog(ERROR, "unsupported target data type for XMLCast");
+				}
+
+				*op->resnull = false;
+			}
 			break;
-	}
+			default:
+				elog(ERROR, "unrecognized XML operation");
+				break;
+			}
 }
 
 /*
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d228318dc7..0e4f0cdc51 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1732,6 +1732,9 @@ exprLocation(const Node *expr)
 		case T_FunctionParameter:
 			loc = ((const FunctionParameter *) expr)->location;
 			break;
+		case T_XmlCast:
+			loc = ((const XmlCast *) expr)->location;
+			break;
 		case T_XmlSerialize:
 			/* XMLSERIALIZE keyword should always be the first thing */
 			loc = ((const XmlSerialize *) expr)->location;
@@ -4464,6 +4467,16 @@ raw_expression_tree_walker_impl(Node *node,
 					return true;
 			}
 			break;
+		case T_XmlCast:
+			{
+				XmlCast   *xc = (XmlCast *) node;
+
+				if (WALK(xc->expr))
+					return true;
+				if (WALK(xc->targetType))
+					return true;
+			}
+			break;
 		case T_CollateClause:
 			return WALK(((CollateClause *) node)->arg);
 		case T_SortBy:
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c3a0a354a9..a615a7b1ba 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -794,7 +794,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	WAIT WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
-	XML_P XMLATTRIBUTES XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
+	XML_P XMLATTRIBUTES XMLCAST XMLCONCAT XMLELEMENT XMLEXISTS XMLFOREST XMLNAMESPACES
 	XMLPARSE XMLPI XMLROOT XMLSERIALIZE XMLTABLE
 
 	YEAR_P YES_P
@@ -16164,6 +16164,24 @@ func_expr_common_subexpr:
 					v->location = @1;
 					$$ = (Node *) v;
 				}
+			| XMLCAST '(' a_expr AS Typename ')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
+			| XMLCAST '(' a_expr AS Typename xml_passing_mech')'
+				{
+					XmlCast *n = makeNode(XmlCast);
+
+					n->expr = $3;
+					n->targetType = $5;
+					n->location = @1;
+					$$ = (Node *) n;
+				}
 			| XMLCONCAT '(' expr_list ')'
 				{
 					$$ = makeXmlExpr(IS_XMLCONCAT, NULL, NIL, $3, @1);
@@ -18237,6 +18255,7 @@ col_name_keyword:
 			| VALUES
 			| VARCHAR
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
@@ -18827,6 +18846,7 @@ bare_label_keyword:
 			| WRITE
 			| XML_P
 			| XMLATTRIBUTES
+			| XMLCAST
 			| XMLCONCAT
 			| XMLELEMENT
 			| XMLEXISTS
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 44fd1385f8..b7f9ba4abb 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -40,6 +40,37 @@
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
+/*
+ * Determines whether a type category is allowed in XMLCAST conversions,
+ * either as a source (SQL -> XML) or target (XML -> SQL) type.
+ *
+ * Based on SQL/XML:2023 (ISO/IEC 9075-14:2023),
+ * Subclause 6.7 "<XML cast specification>", General Rules, item 3.d.ii:
+ *
+ * - Items 1–2 explicitly describe interval mappings:
+ *     1) Year-month intervals -> xs:yearMonthDuration
+ *     2) Day-time intervals   -> xs:dayTimeDuration
+ *
+ * - Items 3–4 describe the general case:
+ *     3) If the target XML type is an XML Schema built-in data type,
+ *     or
+ *     4) If it is derived from a built-in atomic type,
+ *     then that type (or its base type) governs the conversion.
+ *
+ * These built-in and atomic types are defined in "W3C XML Schema Part 2:
+ * Datatypes", and include types such as xs:boolean, xs:decimal, xs:date,
+ * xs:dateTime, and xs:string. While SQL/XML does not enumerate mappings
+ * for all these types, it relies on their existence and semantics to
+ * support conversions.
+ *
+ * As such, PostgreSQL allows casting to and from types in the following
+ * categories: numeric, string, datetime, boolean, and timespan.
+ */
+#define type_is_xmlcast_supported(x) ((x) == TYPCATEGORY_NUMERIC \
+			|| (x) == TYPCATEGORY_STRING || (x) == TYPCATEGORY_DATETIME \
+			|| (x) == TYPCATEGORY_BOOLEAN || (x) == TYPCATEGORY_UNKNOWN \
+			|| (x) == TYPCATEGORY_TIMESPAN)
+
 /* GUC parameters */
 bool		Transform_null_equals = false;
 
@@ -67,6 +98,7 @@ static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
 static Node *transformSQLValueFunction(ParseState *pstate,
 									   SQLValueFunction *svf);
 static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlCast(ParseState *pstate, XmlCast *xc);
 static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
 static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
 static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
@@ -275,6 +307,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 											   (SQLValueFunction *) expr);
 			break;
 
+		case T_XmlCast:
+			result = transformXmlCast(pstate, (XmlCast *) expr);
+			break;
+
 		case T_XmlExpr:
 			result = transformXmlExpr(pstate, (XmlExpr *) expr);
 			break;
@@ -2467,6 +2503,10 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 					newe = coerce_to_specific_type(pstate, newe, INT4OID,
 												   "XMLROOT");
 				break;
+			case IS_XMLCAST:
+				/* not handled here */
+				Assert(false);
+				break;
 			case IS_XMLSERIALIZE:
 				/* not handled here */
 				Assert(false);
@@ -2483,6 +2523,75 @@ transformXmlExpr(ParseState *pstate, XmlExpr *x)
 	return (Node *) newx;
 }
 
+static Node *
+transformXmlCast(ParseState *pstate, XmlCast *xc)
+{
+	Node *result;
+	XmlExpr *xexpr;
+	int32 targetTypmod;
+	Oid targetType;
+	Oid inputType;
+	char inputTypcategory;
+	char targetTypcategory;
+	bool inputTypispreferred;
+	bool targetTypispreferred;
+
+	inputType = exprType(transformExprRecurse(pstate, xc->expr));
+	get_type_category_preferred(inputType, &inputTypcategory, &inputTypispreferred);
+
+	typenameTypeIdAndMod(pstate, xc->targetType, &targetType, &targetTypmod);
+	get_type_category_preferred(targetType, &targetTypcategory, &targetTypispreferred);
+
+	/*
+	 * Ensure that either the cast operand or the data type is an XML,
+	 * and check if the data types are supported.
+	 */
+	if ((inputType != XMLOID && targetType != XMLOID) ||
+		(!type_is_xmlcast_supported(inputTypcategory) && inputType != XMLOID && inputType != BYTEAOID) ||
+		(!type_is_xmlcast_supported(targetTypcategory) && targetType != XMLOID && targetType != BYTEAOID))
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast from '%s' to '%s'",
+						format_type_be(inputType), format_type_be(targetType)),
+				 parser_errposition(pstate, xc->location)));
+
+	/*
+	 * It is not possible to cast some supported data types directly to XML,
+	 * so we first handle them as text and later on return them as XML.
+	 */
+	if ((inputTypcategory == TYPCATEGORY_NUMERIC && inputType != FLOAT4OID &&
+		inputType != FLOAT8OID && inputType != NUMERICOID) || inputType == TIMEOID ||
+		inputType == TIMETZOID || inputType == UNKNOWNOID || inputType == NAMEOID)
+		inputType = TEXTOID;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLCAST;
+	xexpr->location = xc->location;
+	xexpr->type = inputType;
+	xexpr->targetType = targetType;
+	xexpr->name = "xmlcast";
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xc->expr),
+													 inputType,
+													 "XMLCAST"));
+
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   targetType == TEXTOID ? XMLOID : TEXTOID,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   -1);
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLCAST result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+
+	return result;
+}
+
 static Node *
 transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
 {
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 905c975d83..4b2fee64cb 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1955,6 +1955,9 @@ FigureColnameInternal(Node *node, char **name)
 			/* make SQL/XML functions act like a regular function */
 			switch (((XmlExpr *) node)->op)
 			{
+				case IS_XMLCAST:
+					*name = "xmlcast";
+					return 2;
 				case IS_XMLCONCAT:
 					*name = "xmlconcat";
 					return 2;
@@ -1981,6 +1984,10 @@ FigureColnameInternal(Node *node, char **name)
 					break;
 			}
 			break;
+		case T_XmlCast:
+			/* make XMLCAST act like a regular function */
+			*name = "xmlcast";
+			return 2;
 		case T_XmlSerialize:
 			/* make XMLSERIALIZE act like a regular function */
 			*name = "xmlserialize";
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 2501007d98..2278d8154e 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -847,6 +847,28 @@ numeric_is_inf(Numeric num)
 	return NUMERIC_IS_INF(num);
 }
 
+/*
+ * numeric_is_positive_inf() -
+ *
+ *	Is Numeric value positive infinity?
+ */
+bool
+numeric_is_positive_inf(Numeric num)
+{
+	return NUMERIC_IS_PINF(num);
+}
+
+/*
+ * numeric_is_negative_inf() -
+ *
+ *	Is Numeric value negative infinity?
+ */
+bool
+numeric_is_negative_inf(Numeric num)
+{
+	return NUMERIC_IS_NINF(num);
+}
+
 /*
  * numeric_is_integral() -
  *
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 556ab057e5..b69ad29caf 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10119,6 +10119,9 @@ get_rule_expr(Node *node, deparse_context *context,
 					case IS_XMLSERIALIZE:
 						appendStringInfoString(buf, "XMLSERIALIZE(");
 						break;
+					case IS_XMLCAST:
+						appendStringInfoString(buf, "XMLCAST(");
+						break;
 					case IS_DOCUMENT:
 						break;
 				}
@@ -10129,7 +10132,7 @@ get_rule_expr(Node *node, deparse_context *context,
 					else
 						appendStringInfoString(buf, "CONTENT ");
 				}
-				if (xexpr->name)
+				if (xexpr->name && xexpr->op != IS_XMLCAST)
 				{
 					appendStringInfo(buf, "NAME %s",
 									 quote_identifier(map_xml_name_to_sql_identifier(xexpr->name)));
@@ -10165,6 +10168,7 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, ", ");
 					switch (xexpr->op)
 					{
+						case IS_XMLCAST:
 						case IS_XMLCONCAT:
 						case IS_XMLELEMENT:
 						case IS_XMLFOREST:
@@ -10242,6 +10246,10 @@ get_rule_expr(Node *node, deparse_context *context,
 						appendStringInfoString(buf, " NO INDENT");
 				}
 
+				if (xexpr->op == IS_XMLCAST)
+					appendStringInfo(buf, " AS %s",
+									 format_type_be(xexpr->targetType));
+
 				if (xexpr->op == IS_DOCUMENT)
 					appendStringInfoString(buf, " IS DOCUMENT");
 				else
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 41e775570e..4285164891 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -99,6 +99,7 @@
 #include "utils/date.h"
 #include "utils/datetime.h"
 #include "utils/lsyscache.h"
+#include "utils/numeric.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
 #include "utils/xml.h"
@@ -2574,9 +2575,9 @@ map_sql_value_to_xml_value(Datum value, Oid type, bool xml_escape_strings)
 		{
 			case BOOLOID:
 				if (DatumGetBool(value))
-					return "true";
+					return pstrdup("true");
 				else
-					return "false";
+					return pstrdup("false");
 
 			case DATEOID:
 				{
@@ -2706,8 +2707,60 @@ map_sql_value_to_xml_value(Datum value, Oid type, bool xml_escape_strings)
 				}
 #endif							/* USE_LIBXML */
 
-		}
+			case FLOAT4OID:
+				/*
+				 * Special handling for infinity values in floating-point and
+				 * numeric types. The XML Schema specification requires that
+				 * positive infinity be represented as "INF" and negative
+				 * infinity as "-INF" in XML documents for float and double
+				 * types. While decimal types in XML Schema do not support
+				 * infinity, PostgreSQL's NUMERIC type can represent it, so
+				 * we use the same representation for consistency.
+				 *
+				 * See: XML Schema Part 2: Datatypes Second Edition, sections
+				 * 3.2.4 (float) and 3.2.5 (double).
+				 */
+				{
+					float4		val = DatumGetFloat4(value);
+
+					if (isinf(val))
+					{
+						if (val < 0)
+							return pstrdup("-INF");
+						else
+							return pstrdup("INF");
+					}
+				}
+				break;
 
+			case FLOAT8OID:
+				{
+					float8		val = DatumGetFloat8(value);
+
+					if (isinf(val))
+					{
+						if (val < 0)
+							return pstrdup("-INF");
+						else
+							return pstrdup("INF");
+					}
+				}
+				break;
+
+			case NUMERICOID:
+				{
+					Numeric		num = DatumGetNumeric(value);
+
+					if (numeric_is_inf(num))
+					{
+						if (numeric_is_positive_inf(num))
+							return pstrdup("INF");
+						else
+							return pstrdup("-INF");
+					}
+				}
+				break;
+		}
 		/*
 		 * otherwise, just use the type's native text representation
 		 */
@@ -2762,6 +2815,67 @@ escape_xml(const char *str)
 	return buf.data;
 }
 
+/*
+ * Unescape XML escaped characters.
+ *
+ * In order to keep it consistent with "escape_xml(const char*)",
+ * this function intentionally does not depend on libxml2.
+ */
+char *
+unescape_xml(const char *str)
+{
+	StringInfoData buf;
+	size_t p = 0;
+	size_t len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen(str);
+
+	initStringInfo(&buf);
+
+	while (p < len)
+	{
+		if (p + 4 <= len && strncmp(str + p, "&lt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '<');
+			p += 4;
+		}
+		else if (p + 4 <= len && strncmp(str + p, "&gt;", 4) == 0)
+		{
+			appendStringInfoChar(&buf, '>');
+			p += 4;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&amp;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '&');
+			p += 5;
+		}
+		else if (p + 5 <= len && strncmp(str + p, "&#13;", 5) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 5;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&quot;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '"');
+			p += 6;
+		}
+		else if (p + 6 <= len && strncmp(str + p, "&#x0D;", 6) == 0)
+		{
+			appendStringInfoChar(&buf, '\r');
+			p += 6;
+		}
+		else
+		{
+			appendStringInfoChar(&buf, *(str + p));
+			p++;
+		}
+	}
+
+	return buf.data;
+}
 
 static char *
 _SPI_strdup(const char *s)
@@ -4350,6 +4464,7 @@ xml_xpathobjtoxmlarray(xmlXPathObjectPtr xpathobj,
 	datum = PointerGetDatum(cstring_to_xmltype(result_str));
 	(void) accumArrayResult(astate, datum, false,
 							XMLOID, CurrentMemoryContext);
+	pfree(result_str);
 	return 1;
 }
 
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d14294a4ec..c9d097e097 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -877,6 +877,14 @@ typedef struct XmlSerialize
 	ParseLoc	location;		/* token location, or -1 if unknown */
 } XmlSerialize;
 
+typedef struct XmlCast
+{
+	NodeTag		type;
+	Node	   *expr;
+	TypeName   *targetType;
+	ParseLoc	location;		/* token location, or -1 if unknown */
+} XmlCast;
+
 /* Partitioning related definitions */
 
 /*
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1b4436f2ff..77c1be8ff0 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1602,6 +1602,7 @@ typedef struct SQLValueFunction
  */
 typedef enum XmlExprOp
 {
+	IS_XMLCAST,					/* XMLCAST(op AS datatype) */
 	IS_XMLCONCAT,				/* XMLCONCAT(args) */
 	IS_XMLELEMENT,				/* XMLELEMENT(name, xml_attributes, args) */
 	IS_XMLFOREST,				/* XMLFOREST(xml_attributes) */
@@ -1638,6 +1639,8 @@ typedef struct XmlExpr
 	/* target type/typmod for XMLSERIALIZE */
 	Oid			type pg_node_attr(query_jumble_ignore);
 	int32		typmod pg_node_attr(query_jumble_ignore);
+	/* option for XMLCAST */
+	Oid 		targetType;
 	/* token location, or -1 if unknown */
 	ParseLoc	location;
 } XmlExpr;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 5d4fe27ef9..42f98cb7b2 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -510,6 +510,7 @@ PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("xmlcast", XMLCAST, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlelement", XMLELEMENT, COL_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("xmlexists", XMLEXISTS, COL_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/numeric.h b/src/include/utils/numeric.h
index 215f1ea4f5..c57432507e 100644
--- a/src/include/utils/numeric.h
+++ b/src/include/utils/numeric.h
@@ -87,6 +87,8 @@ NumericGetDatum(Numeric X)
  */
 extern bool numeric_is_nan(Numeric num);
 extern bool numeric_is_inf(Numeric num);
+extern bool numeric_is_positive_inf(Numeric num);
+extern bool numeric_is_negative_inf(Numeric num);
 extern int32 numeric_maximum_size(int32 typmod);
 extern char *numeric_out_sci(Numeric num, int scale);
 extern char *numeric_normalize(Numeric num);
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 732dac47bc..7be87e3671 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -80,6 +80,7 @@ extern bool xml_is_document(xmltype *arg);
 extern text *xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg,
 									bool indent);
 extern char *escape_xml(const char *str);
+extern char *unescape_xml(const char *str);
 
 extern char *map_sql_identifier_to_xml_name(const char *ident, bool fully_escaped, bool escape_period);
 extern char *map_xml_name_to_sql_identifier(const char *name);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 103a22a3b1..a5a56c5b74 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1881,3 +1881,610 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof | xmlcast  | pg_typeof |  xmlcast  | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------+----------+-----------+-----------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric   | Infinity | numeric   | -Infinity | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     | xmlcast  |    pg_typeof     |  xmlcast  |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------+----------+------------------+-----------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision | Infinity | double precision | -Infinity | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910 AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 73c411118a..98b2a2878e 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -1496,3 +1496,456 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j':...
                              ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+ERROR:  unsupported XML feature
+LINE 3: '<?xml version="1.0" encoding="utf-8"?>
+        ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+(0 rows)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+(0 rows)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ERROR:  unsupported XML feature
+LINE 1: SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&q...
+                                            ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text B...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY RE...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14':...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('12:30:45'::xml AS time without time zone) = xmlca...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('09:30:10+06:00'::xml AS time with time zone) = xm...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ERROR:  unsupported XML feature
+LINE 4:   xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 yea...
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+ERROR:  unsupported XML feature
+LINE 7:   xmlcast(''::xml AS text) AS c5,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_to_xml
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+SELECT * FROM view_xmlcast_to_xml;
+ERROR:  relation "view_xmlcast_to_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_to_xml;
+                      ^
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+ERROR:  unsupported XML feature
+LINE 3:   xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+                  ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+\sv view_xmlcast_from_xml
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+SELECT * FROM view_xmlcast_from_xml;
+ERROR:  relation "view_xmlcast_from_xml" does not exist
+LINE 1: SELECT * FROM view_xmlcast_from_xml;
+                      ^
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index a85d95358d..5ec57ae5ef 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -1867,3 +1867,612 @@ SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
  x&lt;P&gt;73&lt;/P&gt;0.42truej
 (1 row)
 
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'text[]' at character 8
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+ERROR:  cannot cast from 'xml' to 'integer[]' at character 8
+SELECT xmlcast(NULL AS text);
+ERROR:  cannot cast from 'unknown' to 'text' at character 8
+SELECT xmlcast('foo'::text AS varchar);
+ERROR:  cannot cast from 'text' to 'character varying' at character 8
+SELECT xmlcast(42 AS text);
+ERROR:  cannot cast from 'integer' to 'text' at character 8
+SELECT xmlcast(array['foo','bar'] AS xml);
+ERROR:  cannot cast from 'text[]' to 'xml' at character 8
+\set VERBOSITY default
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+  xmlcast   | pg_typeof |  xmlcast   | pg_typeof 
+------------+-----------+------------+-----------
+ 09-24-2002 | date      | 09-24-2002 | date
+(1 row)
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+                   xmlcast                    | pg_typeof |                   xmlcast                    | pg_typeof 
+----------------------------------------------+-----------+----------------------------------------------+-----------
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval  | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | interval
+(1 row)
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+  xmlcast   |       pg_typeof        |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      |   xmlcast   |      pg_typeof      
+------------+------------------------+-------------+---------------------+-------------+---------------------+-------------+---------------------
+ 09:30:10.5 | time without time zone | 09:30:10+00 | time with time zone | 09:30:10-06 | time with time zone | 09:30:10+06 | time with time zone
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | text      |        foo bar      | text      | foo & <"bar"> | text
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+ xmlcast |     pg_typeof     |       xmlcast       |     pg_typeof     |    xmlcast    |     pg_typeof     
+---------+-------------------+---------------------+-------------------+---------------+-------------------
+ foo bar | character varying |        foo bar      | character varying | foo & <"bar"> | character varying
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | name      |        foo bar      | name      | foo & <"bar"> | name
+(1 row)
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |    xmlcast    | pg_typeof 
+---------+-----------+---------------------+-----------+---------------+-----------
+ foo bar | character |        foo bar      | character | foo & <"bar"> | character
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof | xmlcast  | pg_typeof |  xmlcast  | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------+----------+-----------+-----------+-----------
+ 42.7312345678910 | numeric   | 42.7312345678910 | numeric   | -42.7312345678910 | numeric   | Infinity | numeric   | -Infinity | numeric
+(1 row)
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+     xmlcast     |    pg_typeof     |     xmlcast     |    pg_typeof     |     xmlcast      |    pg_typeof     | xmlcast  |    pg_typeof     |  xmlcast  |    pg_typeof     
+-----------------+------------------+-----------------+------------------+------------------+------------------+----------+------------------+-----------+------------------
+ 42.731234567891 | double precision | 42.731234567891 | double precision | -42.731234567891 | double precision | Infinity | double precision | -Infinity | double precision
+(1 row)
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------+---------+-----------
+      42 | integer   |      42 | integer   |     -42 | integer
+(1 row)
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+     xmlcast      | pg_typeof |     xmlcast      | pg_typeof |      xmlcast      | pg_typeof 
+------------------+-----------+------------------+-----------+-------------------+-----------
+ 4273535420162021 | bigint    | 4273535420162021 | bigint    | -4273535420162021 | bigint
+(1 row)
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof | xmlcast | pg_typeof 
+---------+-----------+---------+-----------
+ t       | boolean   | f       | boolean
+(1 row)
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof 
+---------+-----------
+         | text
+(1 row)
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+ xmlcast | pg_typeof |       xmlcast       | pg_typeof |         xmlcast         | pg_typeof 
+---------+-----------+---------------------+-----------+-------------------------+-----------
+ foo bar | xml       |        foo bar      | xml       | foo &amp; &lt;"bar"&gt; | xml
+(1 row)
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ foo | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+ j | pg_typeof 
+---+-----------
+   | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+ j | pg_typeof 
+---+-----------
+   | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+                 j                 | pg_typeof 
+-----------------------------------+-----------
+ foo &amp; &lt;&quot;bar&quot;&gt; | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+        j        | pg_typeof 
+-----------------+-----------
+ foo & <"bar">\r | text
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 2024-05-29 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+             j              | pg_typeof 
+----------------------------+-----------
+ 2024-05-29T12:04:10.703585 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+       j        | pg_typeof 
+----------------+-----------
+ P1Y2M3DT4H5M6S | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+     j     | pg_typeof 
+-----------+-----------
+ 427353542 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+        j         | pg_typeof 
+------------------+-----------
+ 4273535420162021 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+         j          | pg_typeof 
+--------------------+-----------
+ 42.007312345678910 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+         j         | pg_typeof 
+-------------------+-----------
+ 42.00731234567891 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ -INF | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+  j  | pg_typeof 
+-----+-----------
+ NaN | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+   j   | pg_typeof 
+-------+-----------
+ false | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+  j   | pg_typeof 
+------+-----------
+ true | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+     j      | pg_typeof 
+------------+-----------
+ 11:11:11.5 | xml
+(1 row)
+
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+       j       | pg_typeof 
+---------------+-----------
+ 20:11:11.5+01 | xml
+(1 row)
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+   xmlcast   
+-------------
+ <"foo&bar">
+(1 row)
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ DEADBEEF
+(1 row)
+
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+ xmlcast  
+----------
+ 3q2+7w==
+(1 row)
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+ ?column? | ?column? | ?column? | ?column? 
+----------+----------+----------+----------
+ t        | t        | t        | t
+(1 row)
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+\sv view_xmlcast_to_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_to_xml AS
+ SELECT XMLCAST(NULL::text AS xml)::xml AS c1,
+    XMLCAST('foo'::text AS xml)::xml AS c2,
+    XMLCAST(''::text AS xml)::xml AS c3,
+    XMLCAST(NULL::text AS xml)::xml AS c4,
+    XMLCAST(''::xml AS text)::text AS c5,
+    XMLCAST(NULL::xml AS text)::text AS c6,
+    XMLCAST('foo & <"bar">'::text AS xml)::xml AS c7,
+    XMLCAST('foo & <"bar">'::character varying AS xml)::xml AS c8,
+    XMLCAST('foo & <"bar">'::name::text AS xml)::xml AS c9,
+    XMLCAST(xmltext('foo & <"bar">
+'::text) AS text)::text AS c10,
+    XMLCAST(XMLCAST('foo & <"bar">
+'::text AS xml)::xml AS text)::text AS c11,
+    XMLCAST(to_date('29/05/2024'::text, 'dd/mm/yyyy'::text) AS xml)::xml AS c12,
+    XMLCAST(('Wed May 29 03:04:10.703585 2024 PDT'::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS xml)::xml AS c13,
+    XMLCAST('Wed May 29 12:04:10.703585 2024'::timestamp without time zone AS xml)::xml AS c14,
+    XMLCAST('@ 1 year 2 mons 3 days 4 hours 5 mins 6 secs'::interval AS xml)::xml AS c15,
+    XMLCAST(427353542::text AS xml)::xml AS c16,
+    XMLCAST('4273535420162021'::bigint::text AS xml)::xml AS c17,
+    XMLCAST(42.007312345678910 AS xml)::xml AS c18,
+    XMLCAST(42.007312345678910::double precision AS xml)::xml AS c19,
+    XMLCAST(true AS xml)::xml AS c20,
+    XMLCAST(false AS xml)::xml AS c21,
+    XMLCAST(42 = 73 AS xml)::xml AS c22,
+    XMLCAST(42 <> 73 AS xml)::xml AS c23,
+    XMLCAST('11:11:11.5'::time without time zone::text AS xml)::xml AS c24,
+    XMLCAST(('11:11:11.5-08'::time with time zone AT TIME ZONE 'Europe/Berlin'::text)::text AS xml)::xml AS c25
+SELECT * FROM view_xmlcast_to_xml;
+ c1 | c2  | c3 | c4 | c5 | c6 |                c7                 |                c8                 |                c9                 |       c10       |       c11       |    c12     |            c13             |            c14             |      c15       |    c16    |       c17        |        c18         |        c19        | c20  |  c21  |  c22  | c23  |    c24     |      c25      
+----+-----+----+----+----+----+-----------------------------------+-----------------------------------+-----------------------------------+-----------------+-----------------+------------+----------------------------+----------------------------+----------------+-----------+------------------+--------------------+-------------------+------+-------+-------+------+------------+---------------
+    | foo |    |    |    |    | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo &amp; &lt;&quot;bar&quot;&gt; | foo & <"bar">\r | foo & <"bar">\r | 2024-05-29 | 2024-05-29T12:04:10.703585 | 2024-05-29T12:04:10.703585 | P1Y2M3DT4H5M6S | 427353542 | 4273535420162021 | 42.007312345678910 | 42.00731234567891 | true | false | false | true | 11:11:11.5 | 20:11:11.5+01
+(1 row)
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+\sv view_xmlcast_from_xml
+CREATE OR REPLACE VIEW public.view_xmlcast_from_xml AS
+ SELECT XMLCAST('P1Y2M3DT4H5M6S'::xml AS interval)::interval AS c1,
+    XMLCAST('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval)::interval AS c2,
+    XMLCAST('2002-09-24'::xml AS date)::date AS c3,
+    XMLCAST('2002-09-24+06:00'::xml AS date)::date AS c4,
+    (XMLCAST('09:30:10Z'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c5,
+    (XMLCAST('09:30:10-06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c6,
+    (XMLCAST('09:30:10+06:00'::xml AS time with time zone)::time with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c7,
+    (XMLCAST('2002-05-30T09:30:10Z'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c8,
+    (XMLCAST('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c9,
+    (XMLCAST('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone)::timestamp with time zone AT TIME ZONE 'Europe/Berlin'::text) AS c10,
+    XMLCAST('foo bar'::xml AS text)::text AS c11,
+    XMLCAST('       foo bar     '::xml AS character varying)::character varying AS c12,
+    XMLCAST('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text)::text AS c13,
+    XMLCAST('42.7312345678910'::xml AS numeric)::numeric AS c14,
+    XMLCAST('+42.7312345678910'::xml AS numeric)::numeric AS c15,
+    XMLCAST('-42.7312345678910'::xml AS numeric)::numeric AS c16,
+    XMLCAST('42'::xml AS integer)::integer AS c17,
+    XMLCAST('+42'::xml AS integer)::integer AS c18,
+    XMLCAST('-42'::xml AS integer)::integer AS c19,
+    XMLCAST('4273535420162021'::xml AS bigint)::bigint AS c20,
+    XMLCAST('+4273535420162021'::xml AS bigint)::bigint AS c21,
+    XMLCAST('-4273535420162021'::xml AS bigint)::bigint AS c22,
+    XMLCAST('true'::xml AS boolean)::boolean AS c23,
+    XMLCAST('false'::xml AS boolean)::boolean AS c24,
+    XMLCAST(''::xml AS character varying)::character varying AS c25,
+    XMLCAST(NULL::xml AS character varying)::character varying AS c26
+SELECT * FROM view_xmlcast_from_xml;
+                      c1                      |                      c2                      |     c3     |     c4     |     c5      |     c6      |     c7      |            c8            |            c9            |           c10            |   c11   |         c12         |      c13      |       c14        |       c15        |        c16        | c17 | c18 | c19 |       c20        |       c21        |        c22        | c23 | c24 | c25 | c26 
+----------------------------------------------+----------------------------------------------+------------+------------+-------------+-------------+-------------+--------------------------+--------------------------+--------------------------+---------+---------------------+---------------+------------------+------------------+-------------------+-----+-----+-----+------------------+------------------+-------------------+-----+-----+-----+-----
+ @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | @ 1 year 2 mons 3 days 4 hours 5 mins 6 secs | 09-24-2002 | 09-24-2002 | 10:30:10+01 | 16:30:10+01 | 04:30:10+01 | Thu May 30 11:30:10 2002 | Thu May 30 17:30:10 2002 | Thu May 30 05:30:10 2002 | foo bar |        foo bar      | foo & <"bar"> | 42.7312345678910 | 42.7312345678910 | -42.7312345678910 |  42 |  42 | -42 | 4273535420162021 | 4273535420162021 | -4273535420162021 | t   | f   |     | 
+(1 row)
+
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 0ea4f50883..648751d212 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -679,3 +679,293 @@ SELECT xmltext('  ');
 SELECT xmltext('foo `$_-+?=*^%!|/\()[]{}');
 SELECT xmltext('foo & <"bar">');
 SELECT xmltext('x'|| '<P>73</P>'::xml || .42 || true || 'j'::char);
+
+-- for xmlcast() tests
+INSERT INTO xmltest
+ VALUES (42,
+'<?xml version="1.0" encoding="utf-8"?>
+ <xmlcast>
+  <period1>P1Y2M3DT4H5M6S</period1>
+  <period2>1 year 2 mons 3 days 4 hours 5 minutes 6 seconds</period2>
+  <date1>2002-09-24</date1>
+  <date2>2002-09-24+06:00</date2>
+  <time>09:30:10.5</time>
+  <time_tz1>09:30:10Z</time_tz1>
+  <time_tz2>09:30:10-06:00</time_tz2>
+  <time_tz3>09:30:10+06:00</time_tz3>
+  <timestamp1>2002-05-30T09:00:00</timestamp1>
+  <timestamp2>2002-05-30T09:30:10.5</timestamp2>
+  <timestamp_tz1>2002-05-30T09:30:10Z</timestamp_tz1>
+  <timestamp_tz2>2002-05-30T09:30:10-06:00</timestamp_tz2>
+  <timestamp_tz3>2002-05-30T09:30:10+06:00</timestamp_tz3>
+  <text1>foo bar</text1>
+  <text2>       foo bar     </text2>
+  <text3>foo &amp; &lt;&quot;bar&quot;&gt;</text3>
+  <decimal1>42.7312345678910</decimal1>
+  <decimal2>+42.7312345678910</decimal2>
+  <decimal3>-42.7312345678910</decimal3>
+  <decimal4>INF</decimal4>
+  <decimal5>-INF</decimal5>
+  <integer1>42</integer1>
+  <integer2>+42</integer2>
+  <integer3>-42</integer3>
+  <long1>4273535420162021</long1>
+  <long2>+4273535420162021</long2>
+  <long3>-4273535420162021</long3>
+  <bool1 att="true">42</bool1>
+  <bool2 att="false">73</bool2>
+  <empty></empty>
+ </xmlcast>'::xml
+);
+
+-- This prevents the xmlcast regression tests from failing if the system's timezone has been changed.
+SET timezone TO 'America/Los_Angeles';
+
+-- xmlcast exceptions
+\set VERBOSITY terse
+SELECT xmlcast((xpath('//text1/text()', data))[1] AS text[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast((xpath('//text1/integer1()', data))[1] AS int[]) FROM xmltest WHERE id = 42;
+SELECT xmlcast(NULL AS text);
+SELECT xmlcast('foo'::text AS varchar);
+SELECT xmlcast(42 AS text);
+SELECT xmlcast(array['foo','bar'] AS xml);
+\set VERBOSITY default
+
+-- xmlcast tests for "XML to non-XML" expressions
+SELECT
+  xmlcast((xpath('//date1/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date1/text()', data))[1] AS date)),
+  xmlcast((xpath('//date2/text()', data))[1] AS date), pg_typeof(xmlcast((xpath('//date2/text()', data))[1] AS date))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//period1/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period1/text()', data))[1] AS interval)),
+  xmlcast((xpath('//period2/text()', data))[1] AS interval), pg_typeof(xmlcast((xpath('//period2/text()', data))[1] AS interval))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//time/text()', data))[1] AS time), pg_typeof(xmlcast((xpath('//time/text()', data))[1] AS time)),
+  xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz1/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz2/text()', data))[1] AS time with time zone)),
+  xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone), pg_typeof(xmlcast((xpath('//time_tz3/text()', data))[1] AS time with time zone))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS text)),
+  xmlcast((xpath('//text2/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS text)),
+  xmlcast((xpath('//text3/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS varchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS varchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS varchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS name)),
+  xmlcast((xpath('//text2/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS name)),
+  xmlcast((xpath('//text3/text()', data))[1] AS name), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS name))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text2/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS bpchar)),
+  xmlcast((xpath('//text3/text()', data))[1] AS bpchar), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS bpchar))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS numeric)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS numeric), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS numeric))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//decimal1/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal1/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal2/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal2/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal3/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal3/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal4/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal4/text()', data))[1] AS double precision)),
+  xmlcast((xpath('//decimal5/text()', data))[1] AS double precision), pg_typeof(xmlcast((xpath('//decimal5/text()', data))[1] AS double precision))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//integer1/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer1/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer2/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer2/text()', data))[1] AS int)),
+  xmlcast((xpath('//integer3/text()', data))[1] AS int), pg_typeof(xmlcast((xpath('//integer3/text()', data))[1] AS int))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//long1/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long1/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long2/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long2/text()', data))[1] AS bigint)),
+  xmlcast((xpath('//long3/text()', data))[1] AS bigint), pg_typeof(xmlcast((xpath('//long3/text()', data))[1] AS bigint))
+FROM xmltest WHERE id = 42;
+
+SELECT
+  xmlcast((xpath('//bool1/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean)),
+  xmlcast((xpath('//bool2/@att', data))[1] AS boolean), pg_typeof(xmlcast((xpath('//bool1/@att', data))[1] AS boolean))
+FROM xmltest WHERE id = 42;
+
+SELECT xmlcast((xpath('//empty/text()', data))[1] AS text), pg_typeof(xmlcast((xpath('//empty/text()', data))[1] AS text))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "XML to XML" expressions
+SELECT
+  xmlcast((xpath('//text1/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text1/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text2/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text2/text()', data))[1] AS xml)),
+  xmlcast((xpath('//text3/text()', data))[1] AS xml), pg_typeof(xmlcast((xpath('//text3/text()', data))[1] AS xml))
+FROM xmltest WHERE id = 42;
+
+-- xmlcast tests for "non-XML to XML" expressions
+SELECT j, pg_typeof(j) FROM xmlcast(NULL AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(''::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(NULL::xml AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::text AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::varchar AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('foo & <"bar">'::name AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmltext(E'foo & <"bar">\r') AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(427353542 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(4273535420162021 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42.007312345678910::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::double precision AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('infinity'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('-infinity'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('nan'::numeric AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(true AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(false AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 = 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast(42 <> 73 AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time AS xml) t(j);
+SELECT j, pg_typeof(j) FROM xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) t(j);
+
+-- Convert an XML string to bytea and back to xml
+SELECT xmlcast(convert_from(xmlcast('&lt;&quot;foo&amp;bar&quot;&gt;'::xml AS bytea),'UTF8')::xml AS text);
+
+SET xmlbinary TO hex;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+SET xmlbinary TO base64;
+SELECT xmlcast(E'\\xDEADBEEF'::bytea AS xml);
+
+-- The BY REF and BY VALUE clauses are accepted but ignored.
+-- This checks if the results are indeed the same as without the clauses.
+SELECT
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY REF)::text,
+  xmlcast('foo' AS xml)::text = xmlcast('foo' AS xml BY VALUE)::text,
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY REF),
+  xmlcast('foo'::xml AS text) = xmlcast('foo'::xml AS text BY VALUE);
+
+SELECT
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY REF)::text,
+  xmlcast(42 AS xml)::text = xmlcast(42 AS xml BY VALUE)::text,
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY REF),
+  xmlcast('42'::xml AS int) = xmlcast('42'::xml AS int BY VALUE);
+
+SELECT
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY REF)::text,
+  xmlcast(42.73 AS xml)::text = xmlcast(42.73 AS xml BY VALUE)::text,
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY REF),
+  xmlcast('42.73'::xml AS numeric) = xmlcast('42.73'::xml AS numeric BY VALUE);
+
+SELECT
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY REF)::text,
+  xmlcast('2024-08-14'::date AS xml)::text = xmlcast('2024-08-14'::date AS xml BY VALUE)::text,
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY REF),
+  xmlcast('2024-08-14'::xml AS date) = xmlcast('2024-08-14'::xml AS date BY VALUE);
+
+SELECT
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY REF)::text,
+  xmlcast('12:30:45'::time without time zone AS xml)::text = xmlcast('12:30:45'::time without time zone AS xml BY VALUE)::text,
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY REF),
+  xmlcast('12:30:45'::xml AS time without time zone) = xmlcast('12:30:45'::xml AS time without time zone BY VALUE);
+
+SELECT
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY REF)::text,
+  xmlcast('09:30:10+06:00'::time with time zone AS xml)::text = xmlcast('09:30:10+06:00'::time with time zone AS xml BY VALUE)::text,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY REF),
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) = xmlcast('09:30:10+06:00'::xml AS time with time zone BY VALUE);
+
+SELECT
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY REF)::text,
+  xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml)::text = xmlcast('2002-05-30 09:30:10+06:00'::timestamp with time zone AS xml BY VALUE)::text,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY REF),
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) = xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone BY VALUE);
+
+SELECT
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY REF)::text,
+  xmlcast('1 year 2 mons'::interval AS xml)::text = xmlcast('1 year 2 mons'::interval AS xml BY VALUE)::text,
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY REF),
+  xmlcast('1 year 2 mons'::xml AS interval) = xmlcast('1 year 2 mons'::xml AS interval BY VALUE);
+
+CREATE VIEW view_xmlcast_to_xml AS
+SELECT
+  xmlcast(NULL AS xml) AS c1,
+  xmlcast('foo' AS xml) AS c2,
+  xmlcast(''::text AS xml) AS c3,
+  xmlcast(NULL::text AS xml) AS c4,
+  xmlcast(''::xml AS text) AS c5,
+  xmlcast(NULL::xml AS text) c6,
+  xmlcast('foo & <"bar">'::text AS xml) AS c7,
+  xmlcast('foo & <"bar">'::varchar AS xml) AS c8,
+  xmlcast('foo & <"bar">'::name AS xml) AS c9,
+  xmlcast(xmltext(E'foo & <"bar">\r') AS text) AS c10,
+  xmlcast(xmlcast(E'foo & <"bar">\r' AS xml) AS text) AS c11,
+  xmlcast(to_date('29/05/2024','dd/mm/yyyy') AS xml) AS c12,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp with time zone at time zone 'Europe/Berlin' AS xml) AS c13,
+  xmlcast('2024-05-29 12:04:10.703585+02'::timestamp without time zone AS xml) AS c14,
+  xmlcast('1 year 2 months 3 days 4 hours 5 minutes 6 seconds'::interval AS xml) AS c15,
+  xmlcast(427353542 AS xml) AS c16,
+  xmlcast(4273535420162021 AS xml) AS c17,
+  xmlcast(42.007312345678910 AS xml) AS c18,
+  xmlcast(42.007312345678910::double precision AS xml) AS c19,
+  xmlcast(true AS xml) AS c20,
+  xmlcast(false AS xml) AS c21,
+  xmlcast(42 = 73 AS xml) AS c22,
+  xmlcast(42 <> 73 AS xml) AS c23,
+  xmlcast('11:11:11.5'::time AS xml) AS c24,
+  xmlcast('11:11:11.5'::time with time zone at time zone 'Europe/Berlin' AS xml) AS c25;
+
+\sv view_xmlcast_to_xml
+SELECT * FROM view_xmlcast_to_xml;
+
+CREATE VIEW view_xmlcast_from_xml AS
+SELECT
+  xmlcast('P1Y2M3DT4H5M6S'::xml AS interval) AS c1,
+  xmlcast('1 year 2 mons 3 days 4 hours 5 minutes 6 seconds'::xml AS interval) AS c2,
+  xmlcast('2002-09-24'::xml AS date) AS c3,
+  xmlcast('2002-09-24+06:00'::xml AS date) AS c4,
+  xmlcast('09:30:10Z'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c5,
+  xmlcast('09:30:10-06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c6,
+  xmlcast('09:30:10+06:00'::xml AS time with time zone) at time zone 'Europe/Berlin' AS c7,
+  xmlcast('2002-05-30T09:30:10Z'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c8,
+  xmlcast('2002-05-30T09:30:10-06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c9,
+  xmlcast('2002-05-30T09:30:10+06:00'::xml AS timestamp with time zone) at time zone 'Europe/Berlin' AS c10,
+  xmlcast('foo bar'::xml AS text) AS c11,
+  xmlcast('       foo bar     '::xml AS varchar) AS c12,
+  xmlcast('foo &amp; &lt;&quot;bar&quot;&gt;'::xml AS text) AS c13,
+  xmlcast('42.7312345678910'::xml AS numeric) AS c14,
+  xmlcast('+42.7312345678910'::xml AS numeric) AS c15,
+  xmlcast('-42.7312345678910'::xml AS numeric) AS c16,
+  xmlcast('42'::xml AS integer) AS c17,
+  xmlcast('+42'::xml AS integer) AS c18,
+  xmlcast('-42'::xml AS integer) AS c19,
+  xmlcast('4273535420162021'::xml AS bigint) AS c20,
+  xmlcast('+4273535420162021'::xml AS bigint) AS c21,
+  xmlcast('-4273535420162021'::xml AS bigint) AS c22,
+  xmlcast('true'::xml AS boolean) AS c23,
+  xmlcast('false'::xml AS boolean) AS c24,
+  xmlcast(''::xml AS character varying) AS c25,
+  xmlcast(NULL::xml AS character varying) AS c26;
+
+\sv view_xmlcast_from_xml
+SELECT * FROM view_xmlcast_from_xml;
\ No newline at end of file
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index e3c3523b5b..a33bda3416 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3400,6 +3400,7 @@ XidStatus
 XmlExpr
 XmlExprOp
 XmlOptionType
+XmlCast
 XmlSerialize
 XmlTableBuilderData
 YYLTYPE
-- 
2.43.0