Re: Support to COMMENT ON DATABASE CURRENT_DATABASE

diff --git a/doc/src/sgml/ref/alter_database.sgml b/doc/src/sgml/ref/alter_database.sgml
index 1e09b5d..c9070f9 100644
--- a/doc/src/sgml/ref/alter_database.sgml
+++ b/doc/src/sgml/ref/alter_database.sgml
@@ -31,14 +31,14 @@ ALTER DATABASE <replaceable class="parameter">name</replaceable> [ [ WITH ] <rep
 
 ALTER DATABASE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER DATABASE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
 
 ALTER DATABASE <replaceable class="parameter">name</replaceable> SET TABLESPACE <replaceable class="parameter">new_tablespace</replaceable>
 
-ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET <replaceable>configuration_parameter</replaceable>
-ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET ALL
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> RESET <replaceable>configuration_parameter</replaceable>
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> RESET ALL
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index d705792..d02179f 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -31,7 +31,7 @@ COMMENT ON
   CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
   CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ON DOMAIN <replaceable class="parameter">domain_name</replaceable> |
   CONVERSION <replaceable class="parameter">object_name</replaceable> |
-  DATABASE <replaceable class="parameter">object_name</replaceable> |
+  DATABASE <replaceable class="parameter">database_specification</replaceable> |
   DOMAIN <replaceable class="parameter">object_name</replaceable> |
   EXTENSION <replaceable class="parameter">object_name</replaceable> |
   EVENT TRIGGER <replaceable class="parameter">object_name</replaceable> |
@@ -71,6 +71,11 @@ COMMENT ON
 * |
 [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] |
 [ [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] ] ORDER BY [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ]
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
+
+    object_name
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
@@ -311,6 +316,7 @@ COMMENT ON CONVERSION my_conv IS 'Conversion to UTF8';
 COMMENT ON CONSTRAINT bar_col_cons ON bar IS 'Constrains column col';
 COMMENT ON CONSTRAINT dom_col_constr ON DOMAIN dom IS 'Constrains col of domain';
 COMMENT ON DATABASE my_database IS 'Development Database';
+COMMENT ON DATABASE current_database IS 'Comment on current Database';
 COMMENT ON DOMAIN my_domain IS 'Email Address Domain';
 COMMENT ON EXTENSION hstore IS 'implements the hstore data type';
 COMMENT ON FOREIGN DATA WRAPPER mywrapper IS 'my foreign data wrapper';
diff --git a/doc/src/sgml/ref/security_label.sgml b/doc/src/sgml/ref/security_label.sgml
index ce5a1c1..3e2391b 100644
--- a/doc/src/sgml/ref/security_label.sgml
+++ b/doc/src/sgml/ref/security_label.sgml
@@ -26,7 +26,7 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
   TABLE <replaceable class="parameter">object_name</replaceable> |
   COLUMN <replaceable class="parameter">table_name</replaceable>.<replaceable class="parameter">column_name</replaceable> |
   AGGREGATE <replaceable class="parameter">aggregate_name</replaceable> ( <replaceable>aggregate_signature</replaceable> ) |
-  DATABASE <replaceable class="parameter">object_name</replaceable> |
+  DATABASE <replaceable class="parameter">database_specification</replaceable> |
   DOMAIN <replaceable class="parameter">object_name</replaceable> |
   EVENT TRIGGER <replaceable class="parameter">object_name</replaceable> |
   FOREIGN TABLE <replaceable class="parameter">object_name</replaceable>
@@ -49,6 +49,11 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
 * |
 [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] |
 [ [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] ] ORDER BY [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ]
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
+
+    object_name
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index 8d55c76..519ab55 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -721,7 +721,6 @@ const ObjectAddress InvalidObjectAddress =
 	InvalidOid,
 	0
 };
-
 static ObjectAddress get_object_address_unqualified(ObjectType objtype,
 							   Value *strval, bool missing_ok);
 static ObjectAddress get_relation_by_qualified_name(ObjectType objtype,
@@ -865,6 +864,10 @@ get_object_address(ObjectType objtype, Node *object,
 				}
 				break;
 			case OBJECT_DATABASE:
+				address.classId = DatabaseRelationId;
+				address.objectId = get_dbspec_oid((DbSpec *)object, missing_ok);
+				address.objectSubId = 0;
+				break;
 			case OBJECT_EXTENSION:
 			case OBJECT_TABLESPACE:
 			case OBJECT_ROLE:
@@ -2242,7 +2245,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
 		case OBJECT_DATABASE:
 			if (!pg_database_ownercheck(address.objectId, roleid))
 				aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-							   strVal((Value *) object));
+							   get_dbspec_name((DbSpec *)object));
 			break;
 		case OBJECT_TYPE:
 		case OBJECT_DOMAIN:
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 4f81479..573eefc 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -802,7 +802,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
 	switch (stmt->objectType)
 	{
 		case OBJECT_DATABASE:
-			return AlterDatabaseOwner(strVal((Value *) stmt->object), newowner);
+			return AlterDatabaseOwner((DbSpec *) stmt->object, newowner);
 
 		case OBJECT_SCHEMA:
 			return AlterSchemaOwner(strVal((Value *) stmt->object), newowner);
diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c
index 2dc9371..047d283 100644
--- a/src/backend/commands/comment.c
+++ b/src/backend/commands/comment.c
@@ -52,13 +52,15 @@ CommentObject(CommentStmt *stmt)
 	 */
 	if (stmt->objtype == OBJECT_DATABASE)
 	{
-		char	   *database = strVal((Value *) stmt->object);
-
-		if (!OidIsValid(get_database_oid(database, true)))
+		if (!OidIsValid(get_dbspec_oid((DbSpec *)stmt->object, true)))
 		{
+			char		*dbname = NULL;
+
+			dbname = get_dbspec_name((DbSpec *)stmt->object);
+
 			ereport(WARNING,
 					(errcode(ERRCODE_UNDEFINED_DATABASE),
-					 errmsg("database \"%s\" does not exist", database)));
+					 errmsg("database \"%s\" does not exist", dbname)));
 			return address;
 		}
 	}
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index eb1a469..600b592 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -1413,6 +1413,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	Datum		new_record[Natts_pg_database];
 	bool		new_record_nulls[Natts_pg_database];
 	bool		new_record_repl[Natts_pg_database];
+	char		*dbname = NULL;
+
+	dbname = get_dbspec_name((DbSpec *)stmt->dbspec);
 
 	/* Extract options from the statement node tree */
 	foreach(option, stmt->options)
@@ -1477,7 +1480,7 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 					 parser_errposition(pstate, dtablespace->location)));
 		/* this case isn't allowed within a transaction block */
 		PreventTransactionChain(isTopLevel, "ALTER DATABASE SET TABLESPACE");
-		movedb(stmt->dbname, defGetString(dtablespace));
+		movedb(dbname, defGetString(dtablespace));
 		return InvalidOid;
 	}
 
@@ -1503,20 +1506,20 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	ScanKeyInit(&scankey,
 				Anum_pg_database_datname,
 				BTEqualStrategyNumber, F_NAMEEQ,
-				CStringGetDatum(stmt->dbname));
+				CStringGetDatum(dbname));
 	scan = systable_beginscan(rel, DatabaseNameIndexId, true,
 							  NULL, 1, &scankey);
 	tuple = systable_getnext(scan);
 	if (!HeapTupleIsValid(tuple))
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_DATABASE),
-				 errmsg("database \"%s\" does not exist", stmt->dbname)));
+				 errmsg("database \"%s\" does not exist", dbname)));
 
 	dboid = HeapTupleGetOid(tuple);
 
 	if (!pg_database_ownercheck(HeapTupleGetOid(tuple), GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-					   stmt->dbname);
+					   dbname);
 
 	/*
 	 * In order to avoid getting locked out and having to go through
@@ -1574,7 +1577,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 Oid
 AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 {
-	Oid			datid = get_database_oid(stmt->dbname, false);
+	Oid			datid;
+
+	datid = get_dbspec_oid((DbSpec *)stmt->dbspec, false);
 
 	/*
 	 * Obtain a lock on the database and make sure it didn't go away in the
@@ -1584,7 +1589,7 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 
 	if (!pg_database_ownercheck(datid, GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-					   stmt->dbname);
+				get_dbspec_name((DbSpec *)stmt->dbspec));
 
 	AlterSetting(datid, InvalidOid, stmt->setstmt);
 
@@ -1598,7 +1603,7 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
  * ALTER DATABASE name OWNER TO newowner
  */
 ObjectAddress
-AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
+AlterDatabaseOwner(const DbSpec *dbspec, Oid newOwnerId)
 {
 	Oid			db_id;
 	HeapTuple	tuple;
@@ -1607,6 +1612,9 @@ AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
 	SysScanDesc scan;
 	Form_pg_database datForm;
 	ObjectAddress address;
+	char		*dbname;
+
+	dbname = get_dbspec_name(dbspec);
 
 	/*
 	 * Get the old tuple.  We don't need a lock on the database per se,
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 6c4612d..7172125 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -2043,6 +2043,7 @@ ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op)
 			*op->resnull = fcinfo.isnull;
 			break;
 		case SVFOP_CURRENT_CATALOG:
+		case SVFOP_CURRENT_DATABASE:
 			InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
 			*op->resvalue = current_database(&fcinfo);
 			*op->resnull = fcinfo.isnull;
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index d9ff8a7..933378a 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2922,6 +2922,18 @@ _copyTriggerTransition(const TriggerTransition *from)
 	return newnode;
 }
 
+static DbSpec *
+_copyDatabaseSpec(const DbSpec *from)
+{
+	DbSpec   *newnode = makeNode(DbSpec);
+
+	COPY_SCALAR_FIELD(dbtype);
+	COPY_STRING_FIELD(dbname);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
 static Query *
 _copyQuery(const Query *from)
 {
@@ -3734,7 +3746,7 @@ _copyAlterDatabaseStmt(const AlterDatabaseStmt *from)
 {
 	AlterDatabaseStmt *newnode = makeNode(AlterDatabaseStmt);
 
-	COPY_STRING_FIELD(dbname);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(options);
 
 	return newnode;
@@ -3745,7 +3757,7 @@ _copyAlterDatabaseSetStmt(const AlterDatabaseSetStmt *from)
 {
 	AlterDatabaseSetStmt *newnode = makeNode(AlterDatabaseSetStmt);
 
-	COPY_STRING_FIELD(dbname);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(setstmt);
 
 	return newnode;
@@ -5548,7 +5560,9 @@ copyObjectImpl(const void *from)
 		case T_PartitionCmd:
 			retval = _copyPartitionCmd(from);
 			break;
-
+		case T_DbSpec:
+			retval = _copyDatabaseSpec(from);
+			break;
 			/*
 			 * MISCELLANEOUS NODES
 			 */
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 2866fd7..3570514 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1635,7 +1635,7 @@ _equalCreatedbStmt(const CreatedbStmt *a, const CreatedbStmt *b)
 static bool
 _equalAlterDatabaseStmt(const AlterDatabaseStmt *a, const AlterDatabaseStmt *b)
 {
-	COMPARE_STRING_FIELD(dbname);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(options);
 
 	return true;
@@ -1644,7 +1644,7 @@ _equalAlterDatabaseStmt(const AlterDatabaseStmt *a, const AlterDatabaseStmt *b)
 static bool
 _equalAlterDatabaseSetStmt(const AlterDatabaseSetStmt *a, const AlterDatabaseSetStmt *b)
 {
-	COMPARE_STRING_FIELD(dbname);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(setstmt);
 
 	return true;
@@ -2877,6 +2877,16 @@ _equalPartitionCmd(const PartitionCmd *a, const PartitionCmd *b)
 	return true;
 }
 
+static bool
+_equalDatabaseSpec(const DbSpec *a, const DbSpec *b)
+{
+	COMPARE_SCALAR_FIELD(dbtype);
+	COMPARE_STRING_FIELD(dbname);
+	COMPARE_LOCATION_FIELD(location);
+
+	return true;
+}
+
 /*
  * Stuff from pg_list.h
  */
@@ -3690,6 +3700,9 @@ equal(const void *a, const void *b)
 		case T_PartitionCmd:
 			retval = _equalPartitionCmd(a, b);
 			break;
+		case T_DbSpec:
+			retval = _equalDatabaseSpec(a, b);
+			break;
 
 		default:
 			elog(ERROR, "unrecognized node type: %d",
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c301ca4..431a287 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -187,7 +187,7 @@ static void processCASbits(int cas_bits, int location, const char *constrType,
 			   bool *deferrable, bool *initdeferred, bool *not_valid,
 			   bool *no_inherit, core_yyscan_t yyscanner);
 static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
-
+static Node *makeDbSpec(DbSpecType type, int location);
 %}
 
 %pure-parser
@@ -572,6 +572,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				opt_frame_clause frame_extent frame_bound
 %type <str>		opt_existing_window_name
 %type <boolean> opt_if_not_exists
+%type <node>	db_spec_name
 %type <ival>	generated_when override_kind
 %type <partspec>	PartitionSpec OptPartitionSpec
 %type <str>			part_strategy
@@ -617,7 +618,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	COMMITTED CONCURRENTLY CONFIGURATION CONFLICT CONNECTION CONSTRAINT
 	CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE
 	CROSS CSV CUBE CURRENT_P
-	CURRENT_CATALOG CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
+	CURRENT_CATALOG CURRENT_DATABASE CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
 
 	DATA_P DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
@@ -6367,6 +6368,14 @@ CommentStmt:
 					n->comment = $6;
 					$$ = (Node *) n;
 				}
+			| COMMENT ON DATABASE db_spec_name IS comment_text
+				{
+					CommentStmt *n = makeNode(CommentStmt);
+					n->objtype = OBJECT_DATABASE;
+					n->object = (Node *) $4;
+					n->comment = $6;
+					$$ = (Node *) n;
+				}
 			| COMMENT ON TYPE_P Typename IS comment_text
 				{
 					CommentStmt *n = makeNode(CommentStmt);
@@ -6515,7 +6524,6 @@ comment_type_any_name:
 /* object types taking name */
 comment_type_name:
 			ACCESS METHOD						{ $$ = OBJECT_ACCESS_METHOD; }
-			| DATABASE							{ $$ = OBJECT_DATABASE; }
 			| EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
 			| EXTENSION							{ $$ = OBJECT_EXTENSION; }
 			| FOREIGN DATA_P WRAPPER			{ $$ = OBJECT_FDW; }
@@ -6564,6 +6572,16 @@ SecLabelStmt:
 					n->label = $8;
 					$$ = (Node *) n;
 				}
+			| SECURITY LABEL opt_provider ON DATABASE db_spec_name
+			IS security_label
+				{
+					SecLabelStmt *n = makeNode(SecLabelStmt);
+					n->provider = $3;
+					n->objtype = OBJECT_DATABASE;
+					n->object = (Node *) $6;
+					n->label = $8;
+					$$ = (Node *) n;
+				}
 			| SECURITY LABEL opt_provider ON TYPE_P Typename
 			  IS security_label
 				{
@@ -6632,8 +6650,7 @@ security_label_type_any_name:
 
 /* object types taking name */
 security_label_type_name:
-			DATABASE							{ $$ = OBJECT_DATABASE; }
-			| EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
+			EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
 			| opt_procedural LANGUAGE			{ $$ = OBJECT_LANGUAGE; }
 			| PUBLICATION						{ $$ = OBJECT_PUBLICATION; }
 			| ROLE								{ $$ = OBJECT_ROLE; }
@@ -9062,11 +9079,11 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
 					n->newowner = $6;
 					$$ = (Node *)n;
 				}
-			| ALTER DATABASE database_name OWNER TO RoleSpec
+			| ALTER DATABASE db_spec_name OWNER TO RoleSpec
 				{
 					AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
 					n->objectType = OBJECT_DATABASE;
-					n->object = (Node *) makeString($3);
+					n->object = (Node *) $3;
 					n->newowner = $6;
 					$$ = (Node *)n;
 				}
@@ -9872,24 +9889,24 @@ opt_equal:	'='										{}
  *****************************************************************************/
 
 AlterDatabaseStmt:
-			ALTER DATABASE database_name WITH createdb_opt_list
+			ALTER DATABASE db_spec_name WITH createdb_opt_list
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = $5;
 					$$ = (Node *)n;
 				 }
-			| ALTER DATABASE database_name createdb_opt_list
+			| ALTER DATABASE db_spec_name createdb_opt_list
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = $4;
 					$$ = (Node *)n;
 				 }
-			| ALTER DATABASE database_name SET TABLESPACE name
+			| ALTER DATABASE db_spec_name SET TABLESPACE name
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = list_make1(makeDefElem("tablespace",
 														(Node *)makeString($6), @6));
 					$$ = (Node *)n;
@@ -9897,10 +9914,10 @@ AlterDatabaseStmt:
 		;
 
 AlterDatabaseSetStmt:
-			ALTER DATABASE database_name SetResetClause
+			ALTER DATABASE db_spec_name SetResetClause
 				{
 					AlterDatabaseSetStmt *n = makeNode(AlterDatabaseSetStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->setstmt = $4;
 					$$ = (Node *)n;
 				}
@@ -13429,6 +13446,10 @@ func_expr_common_subexpr:
 				{
 					$$ = makeSQLValueFunction(SVFOP_SESSION_USER, -1, @1);
 				}
+			| CURRENT_DATABASE
+				{
+					$$ = makeSQLValueFunction(SVFOP_CURRENT_DATABASE, -1, @1);
+				}
 			| USER
 				{
 					$$ = makeSQLValueFunction(SVFOP_USER, -1, @1);
@@ -14399,7 +14420,29 @@ name_list:	name
 name:		ColId									{ $$ = $1; };
 
 database_name:
-			ColId									{ $$ = $1; };
+			ColId									{ $$ = $1; }
+			| CURRENT_DATABASE
+				{
+					ereport(ERROR,
+							(errcode(ERRCODE_RESERVED_NAME),
+							 errmsg("%s cannot be used as a database name here",
+									"CURRENT_DATABASE"),
+							 parser_errposition(@1)));
+				}
+		;
+
+db_spec_name:
+			ColId
+				{
+					DbSpec *n = (DbSpec *) makeDbSpec(DBSPEC_CSTRING, @1);
+					n->dbname = pstrdup($1);
+					$$ = (Node *)n;
+				}
+			| CURRENT_DATABASE
+				{
+					$$ = (Node *) makeDbSpec(DBSPEC_CURRENT_DATABASE, @1);
+				}
+		;
 
 access_method:
 			ColId									{ $$ = $1; };
@@ -14425,6 +14468,8 @@ func_name:	type_function_name
 						$$ = check_func_name(lcons(makeString($1), $2),
 											 yyscanner);
 					}
+			| CURRENT_DATABASE
+					{ $$ = list_make1(makeString("current_database")); }
 		;
 
 
@@ -15076,6 +15121,7 @@ reserved_keyword:
 			| CONSTRAINT
 			| CREATE
 			| CURRENT_CATALOG
+			| CURRENT_DATABASE
 			| CURRENT_DATE
 			| CURRENT_ROLE
 			| CURRENT_TIME
@@ -15987,6 +16033,20 @@ makeRecursiveViewSelect(char *relname, List *aliases, Node *query)
 	return (Node *) s;
 }
 
+/* makeDbSpec
+ * Create a DbSpec with the given type
+ */
+static Node *
+makeDbSpec(DbSpecType type, int location)
+{
+	DbSpec *spec = makeNode(DbSpec);
+
+	spec->dbtype = type;
+	spec->location = location;
+
+	return (Node *) spec;
+}
+
 /* parser_init()
  * Initialize to parse one query string
  */
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 86d1da0..82a6c5f 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -2328,6 +2328,7 @@ transformSQLValueFunction(ParseState *pstate, SQLValueFunction *svf)
 		case SVFOP_SESSION_USER:
 		case SVFOP_CURRENT_CATALOG:
 		case SVFOP_CURRENT_SCHEMA:
+		case SVFOP_CURRENT_DATABASE:
 			svf->type = NAMEOID;
 			break;
 	}
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 21593b2..508fd41 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1882,6 +1882,9 @@ FigureColnameInternal(Node *node, char **name)
 				case SVFOP_CURRENT_SCHEMA:
 					*name = "current_schema";
 					return 2;
+				case SVFOP_CURRENT_DATABASE:
+					*name = "current_database";
+					return 2;
 			}
 			break;
 		case T_XmlExpr:
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index fa6b792..a9f468a 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -24,6 +24,7 @@
 #include "catalog/pg_auth_members.h"
 #include "catalog/pg_type.h"
 #include "catalog/pg_class.h"
+#include "catalog/pg_database.h"
 #include "commands/dbcommands.h"
 #include "commands/proclang.h"
 #include "commands/tablespace.h"
@@ -5270,3 +5271,66 @@ check_rolespec_name(const RoleSpec *role, const char *detail_msg)
 							role->rolename)));
 	}
 }
+
+
+/*
+ * Given a DbSpec, returns a palloc'ed copy of the corresponding role's name.
+ */
+char *
+get_dbspec_name(const DbSpec *db)
+{
+	char	   *dbname;
+	HeapTuple	tuple;
+	Form_pg_database dbForm;
+
+	switch (db->dbtype)
+	{
+		case DBSPEC_CSTRING:
+			Assert(db->dbname);
+			dbname = db->dbname;
+			break;
+
+		case DBSPEC_CURRENT_DATABASE:
+			tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
+			if (!HeapTupleIsValid(tuple))
+				elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
+
+			dbForm = (Form_pg_database) GETSTRUCT(tuple);
+			dbname = pstrdup(NameStr(dbForm->datname));
+			ReleaseSysCache(tuple);
+			break;
+
+		default:
+			elog(ERROR, "unexpected database type %d", db->dbtype);
+	}
+
+
+	return dbname;
+}
+
+/*
+ * Given a DbSpec node, return the OID it corresponds to.  If missing_ok is
+ * true, return InvalidOid if the database does not exist.
+ */
+Oid
+get_dbspec_oid(const DbSpec *db, bool missing_ok)
+{
+	Oid			oid;
+
+	switch (db->dbtype)
+	{
+		case DBSPEC_CSTRING:
+			Assert(db->dbname);
+			oid = get_database_oid(db->dbname, missing_ok);
+			break;
+
+		case DBSPEC_CURRENT_DATABASE:
+			oid = MyDatabaseId;
+			break;
+
+		default:
+			elog(ERROR, "unexpected database type %d", db->dbtype);
+	}
+
+	return oid;
+}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 06cf32f..8478c60 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8351,6 +8351,10 @@ get_rule_expr(Node *node, deparse_context *context,
 					case SVFOP_CURRENT_SCHEMA:
 						appendStringInfoString(buf, "CURRENT_SCHEMA");
 						break;
+					case SVFOP_CURRENT_DATABASE:
+						appendStringInfoString(buf, "CURRENT_DATABASE");
+						break;
+
 				}
 			}
 			break;
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index f42c8cd..9221b54 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -24,7 +24,8 @@ extern void dropdb(const char *dbname, bool missing_ok);
 extern ObjectAddress RenameDatabase(const char *oldname, const char *newname);
 extern Oid	AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel);
 extern Oid	AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
-extern ObjectAddress AlterDatabaseOwner(const char *dbname, Oid newOwnerId);
+extern ObjectAddress AlterDatabaseOwner(const DbSpec *dbspec, Oid newOwnerId);
+
 
 extern Oid	get_database_oid(const char *dbname, bool missingok);
 extern char *get_database_name(Oid dbid);
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index ffeeb49..7847af5 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -462,6 +462,7 @@ typedef enum NodeTag
 	T_OnConflictClause,
 	T_CommonTableExpr,
 	T_RoleSpec,
+	T_DbSpec,
 	T_TriggerTransition,
 	T_PartitionElem,
 	T_PartitionSpec,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 34d6afc..4852c7d 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3023,6 +3023,24 @@ typedef struct LoadStmt
 	char	   *filename;		/* file to load */
 } LoadStmt;
 
+
+/*
+ * DbSpecType - The type of a database name.
+ */
+typedef enum DbSpecType
+{
+	DBSPEC_CSTRING,				/* database name is stored as a C string */
+	DBSPEC_CURRENT_DATABASE		/* database name is CURRENT_DATABASE */
+} DbSpecType;
+
+typedef struct DbSpec
+{
+	NodeTag			type;
+	DbSpecType		dbtype;			/* Type of the database */
+	char			*dbname;		/* filled only for DBSPEC_CSTRING */
+	int				location;		/* token location, or -1 if unknown */
+} DbSpec;
+
 /* ----------------------
  *		Createdb Statement
  * ----------------------
@@ -3041,14 +3059,14 @@ typedef struct CreatedbStmt
 typedef struct AlterDatabaseStmt
 {
 	NodeTag		type;
-	char	   *dbname;			/* name of database to alter */
-	List	   *options;		/* List of DefElem nodes */
+	Node		*dbspec;		/* name of database to alter, DbSpec */
+	List	   	*options;		/* List of DefElem nodes */
 } AlterDatabaseStmt;
 
 typedef struct AlterDatabaseSetStmt
 {
 	NodeTag		type;
-	char	   *dbname;			/* database name */
+	Node		*dbspec;			/* DbSpec */
 	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterDatabaseSetStmt;
 
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 074ae0a..c65a05c 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1102,7 +1102,8 @@ typedef enum SQLValueFunctionOp
 	SVFOP_USER,
 	SVFOP_SESSION_USER,
 	SVFOP_CURRENT_CATALOG,
-	SVFOP_CURRENT_SCHEMA
+	SVFOP_CURRENT_SCHEMA,
+	SVFOP_CURRENT_DATABASE
 } SQLValueFunctionOp;
 
 typedef struct SQLValueFunction
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index f50e45e..a022826 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -104,6 +104,7 @@ PG_KEYWORD("csv", CSV, UNRESERVED_KEYWORD)
 PG_KEYWORD("cube", CUBE, UNRESERVED_KEYWORD)
 PG_KEYWORD("current", CURRENT_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("current_catalog", CURRENT_CATALOG, RESERVED_KEYWORD)
+PG_KEYWORD("current_database", CURRENT_DATABASE, RESERVED_KEYWORD)
 PG_KEYWORD("current_date", CURRENT_DATE, RESERVED_KEYWORD)
 PG_KEYWORD("current_role", CURRENT_ROLE, RESERVED_KEYWORD)
 PG_KEYWORD("current_schema", CURRENT_SCHEMA, TYPE_FUNC_NAME_KEYWORD)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 254a811..c9cfa85 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -246,6 +246,8 @@ extern Oid	get_rolespec_oid(const RoleSpec *role, bool missing_ok);
 extern void check_rolespec_name(const RoleSpec *role, const char *detail_msg);
 extern HeapTuple get_rolespec_tuple(const RoleSpec *role);
 extern char *get_rolespec_name(const RoleSpec *role);
+extern char *get_dbspec_name(const DbSpec *db);
+extern Oid  get_dbspec_oid(const DbSpec *db, bool missing_ok);
 
 extern void select_best_grantor(Oid roleId, AclMode privileges,
 					const Acl *acl, Oid ownerId,
diff --git a/src/test/regress/expected/dbname.out b/src/test/regress/expected/dbname.out
new file mode 100644
index 0000000..cac34de
--- /dev/null
+++ b/src/test/regress/expected/dbname.out
@@ -0,0 +1,113 @@
+CREATE ROLE dbuser1 with LOGIN;
+CREATE ROLE dbuser2 with SUPERUSER LOGIN;
+CREATE ROLE dbuser3 with SUPERUSER LOGIN;
+DROP DATABASE IF EXISTS db1;
+NOTICE:  database "db1" does not exist, skipping
+CREATE DATABASE db1 with owner=dbuser1;
+CREATE DATABASE "current_database" with owner=dbuser1;
+CREATE DATABASE current_database with owner=dbuser1;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: CREATE DATABASE current_database with owner=dbuser1;
+                        ^
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       | Description 
+------------------+-------------
+ current_database | 
+ db1              | 
+(2 rows)
+
+\c db1;
+SELECT CURRENT_DATABASE;
+ current_database 
+------------------
+ db1
+(1 row)
+
+COMMENT ON DATABASE current_database IS 'db1';
+COMMENT ON DATABASE "current_database" IS 'db2';
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       | Description 
+------------------+-------------
+ current_database | db2
+ db1              | db1
+(2 rows)
+
+-- test alter owner
+ALTER DATABASE current_database OWNER to dbuser2; 
+ALTER DATABASE "current_database" OWNER to dbuser2;
+SELECT d.datname as "Name",
+       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       |  Owner  | Description 
+------------------+---------+-------------
+ current_database | dbuser2 | db2
+ db1              | dbuser2 | db1
+(2 rows)
+
+-- test alter database tablespace
+ALTER DATABASE current_database SET TABLESPACE pg_default;
+ERROR:  cannot change the tablespace of the currently open database
+ALTER DATABASE "current_database" SET TABLESPACE pg_default;
+-- test alter database rename
+ALTER DATABASE current_database rename to db2;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: ALTER DATABASE current_database rename to db2;
+                       ^
+COMMENT ON DATABASE "current_database" IS 'changed from current_database';
+ALTER DATABASE "current_database" rename to db2;
+ALTER DATABASE db2 rename to current_database;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: ALTER DATABASE db2 rename to current_database;
+                                     ^
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1' or d.datname='db2'
+ORDER BY 1;
+ Name |          Description          
+------+-------------------------------
+ db1  | db1
+ db2  | changed from current_database
+(2 rows)
+
+-- test alter database set parameter
+ALTER DATABASE current_database SET parallel_tuple_cost=0.3;
+\c db1
+show parallel_tuple_cost;
+ parallel_tuple_cost 
+---------------------
+ 0.3
+(1 row)
+
+ALTER DATABASE current_database RESET parallel_tuple_cost;
+\c db1
+show parallel_tuple_cost;
+ parallel_tuple_cost 
+---------------------
+ 0.1
+(1 row)
+
+-- clean up
+\c postgres
+DROP DATABASE IF EXISTS "current_database";
+NOTICE:  database "current_database" does not exist, skipping
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db2;
+DROP ROLE dbuser1;
+DROP ROLE dbuser2;
+DROP ROLE dbuser3;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index aa5e6af..6a6382c 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -123,3 +123,4 @@ test: event_trigger
 
 # run stats by itself because its delay may be insufficient under heavy load
 test: stats
+test: dbname
\ No newline at end of file
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 3866314..96e6202 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -183,3 +183,4 @@ test: partition_join
 test: reloptions
 test: event_trigger
 test: stats
+test: dbname
diff --git a/src/test/regress/sql/dbname.sql b/src/test/regress/sql/dbname.sql
new file mode 100644
index 0000000..5c8b36e
--- /dev/null
+++ b/src/test/regress/sql/dbname.sql
@@ -0,0 +1,77 @@
+CREATE ROLE dbuser1 with LOGIN;
+CREATE ROLE dbuser2 with SUPERUSER LOGIN;
+CREATE ROLE dbuser3 with SUPERUSER LOGIN;
+
+DROP DATABASE IF EXISTS db1;
+CREATE DATABASE db1 with owner=dbuser1;
+CREATE DATABASE "current_database" with owner=dbuser1;
+CREATE DATABASE current_database with owner=dbuser1;
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+
+\c db1;
+SELECT CURRENT_DATABASE;
+
+
+COMMENT ON DATABASE current_database IS 'db1';
+COMMENT ON DATABASE "current_database" IS 'db2';
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+-- test alter owner
+ALTER DATABASE current_database OWNER to dbuser2; 
+ALTER DATABASE "current_database" OWNER to dbuser2;
+
+SELECT d.datname as "Name",
+       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+-- test alter database tablespace
+ALTER DATABASE current_database SET TABLESPACE pg_default;
+ALTER DATABASE "current_database" SET TABLESPACE pg_default;
+
+-- test alter database rename
+ALTER DATABASE current_database rename to db2;
+COMMENT ON DATABASE "current_database" IS 'changed from current_database';
+ALTER DATABASE "current_database" rename to db2;
+ALTER DATABASE db2 rename to current_database;
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1' or d.datname='db2'
+ORDER BY 1;
+
+-- test alter database set parameter
+ALTER DATABASE current_database SET parallel_tuple_cost=0.3;
+\c db1
+show parallel_tuple_cost;
+ALTER DATABASE current_database RESET parallel_tuple_cost;
+\c db1
+show parallel_tuple_cost;
+
+-- clean up
+\c postgres
+
+DROP DATABASE IF EXISTS "current_database";
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db2;
+DROP ROLE dbuser1;
+DROP ROLE dbuser2;
+DROP ROLE dbuser3;

diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 70d8f24..12ea7dc 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -670,6 +670,7 @@ emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
 		appendPQExpBuffer(buffer,
 						  "SECURITY LABEL FOR %s ON %s",
 						  fmtId(provider), target);
+
 		appendPQExpBuffer(buffer,
 						  " %s IS ",
 						  fmtId(objname));
@@ -679,6 +680,40 @@ emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
 }
 
 /*
+ * emitDatabaseSecLabels
+ *
+ * Format security label data on database.
+ */
+void
+emitDatabaseSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
+				const char *objname, bool current_datbase)
+{
+	int			i;
+
+	for (i = 0; i < PQntuples(res); i++)
+	{
+		char	   *provider = PQgetvalue(res, i, 0);
+		char	   *label = PQgetvalue(res, i, 1);
+
+		/* must use fmtId result before calling it again */
+		appendPQExpBuffer(buffer,
+						  "SECURITY LABEL FOR %s ON DATABASE",
+						  fmtId(provider));
+
+		if(current_datbase)
+			appendPQExpBuffer(buffer," CURRENT_DATABASE IS ");
+		else
+		{
+			appendPQExpBuffer(buffer,
+							  " %s IS ",
+							  fmtId(objname));
+		}
+		appendStringLiteralConn(buffer, label, conn);
+		appendPQExpBufferStr(buffer, ";\n");
+	}
+}
+
+/*
  * buildACLQueries
  *
  * Build the subqueries to extract out the correct set of ACLs to be
diff --git a/src/bin/pg_dump/dumputils.h b/src/bin/pg_dump/dumputils.h
index fe364dd..cee625b 100644
--- a/src/bin/pg_dump/dumputils.h
+++ b/src/bin/pg_dump/dumputils.h
@@ -49,8 +49,10 @@ extern bool buildDefaultACLCommands(const char *type, const char *nspname,
 extern void buildShSecLabelQuery(PGconn *conn, const char *catalog_name,
 					 uint32 objectId, PQExpBuffer sql);
 extern void emitShSecLabels(PGconn *conn, PGresult *res,
-				PQExpBuffer buffer, const char *target, const char *objname);
-
+				PQExpBuffer buffer, const char *target,
+				const char *objname);
+extern void emitDatabaseSecLabels(PGconn *conn, PGresult *res,
+				PQExpBuffer buffer, const char *objname, bool current_datbase);
 extern void buildACLQueries(PQExpBuffer acl_subquery, PQExpBuffer racl_subquery,
 				PQExpBuffer init_acl_subquery, PQExpBuffer init_racl_subquery,
 				const char *acl_column, const char *acl_owner,
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index d8fb356..d0d9545 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -2803,7 +2803,10 @@ dumpDatabase(Archive *fout)
 			 * Generates warning when loaded into a differently-named
 			 * database.
 			 */
-			appendPQExpBuffer(dbQry, "COMMENT ON DATABASE %s IS ", fmtId(datname));
+			if (fout->remoteVersion >= 110000)
+				appendPQExpBuffer(dbQry, "COMMENT ON DATABASE CURRENT_DATABASE IS ");
+			else
+				appendPQExpBuffer(dbQry, "COMMENT ON DATABASE %s IS ", fmtId(datname));
 			appendStringLiteralAH(dbQry, comment, fout);
 			appendPQExpBufferStr(dbQry, ";\n");
 
@@ -2832,7 +2835,10 @@ dumpDatabase(Archive *fout)
 		buildShSecLabelQuery(conn, "pg_database", dbCatId.oid, seclabelQry);
 		shres = ExecuteSqlQuery(fout, seclabelQry->data, PGRES_TUPLES_OK);
 		resetPQExpBuffer(seclabelQry);
-		emitShSecLabels(conn, shres, seclabelQry, "DATABASE", datname);
+		if (fout->remoteVersion >= 110000)
+			emitDatabaseSecLabels(conn, shres, seclabelQry, datname, true);
+		else
+			emitDatabaseSecLabels(conn, shres, seclabelQry, datname, false);
 		if (strlen(seclabelQry->data))
 			ArchiveEntry(fout, dbCatId, createDumpId(), datname, NULL, NULL,
 						 dba, false, "SECURITY LABEL", SECTION_NONE,
@@ -14774,9 +14780,17 @@ dumpSecLabel(Archive *fout, const char *target,
 		if (labels[i].objsubid != subid)
 			continue;
 
-		appendPQExpBuffer(query,
-						  "SECURITY LABEL FOR %s ON %s IS ",
-						  fmtId(labels[i].provider), target);
+		if (fout->remoteVersion >= 110000 && (strncmp(target, "DATABASE", 8) != 0))
+		{
+			appendPQExpBuffer(query,
+							  "SECURITY LABEL FOR %s ON DATABASE CURRENT_DATABASE IS ",
+							  fmtId(labels[i].provider));
+		}
+		else
+			appendPQExpBuffer(query,
+							  "SECURITY LABEL FOR %s ON %s IS ",
+							  fmtId(labels[i].provider), target);
+
 		appendStringLiteralAH(query, labels[i].label, fout);
 		appendPQExpBufferStr(query, ";\n");
 	}

diff --git a/doc/src/sgml/ref/alter_role.sgml b/doc/src/sgml/ref/alter_role.sgml
index c135364..28bcc07 100644
--- a/doc/src/sgml/ref/alter_role.sgml
+++ b/doc/src/sgml/ref/alter_role.sgml
@@ -38,16 +38,21 @@ ALTER ROLE <replaceable class="parameter">role_specification</replaceable> [ WIT
 
 ALTER ROLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET ALL
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET ALL
 
 <phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
 
     <replaceable class="parameter">role_name</replaceable>
   | CURRENT_USER
   | SESSION_USER
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/alter_user.sgml b/doc/src/sgml/ref/alter_user.sgml
index 8e03510..b33d87d 100644
--- a/doc/src/sgml/ref/alter_user.sgml
+++ b/doc/src/sgml/ref/alter_user.sgml
@@ -38,16 +38,21 @@ ALTER USER <replaceable class="parameter">role_specification</replaceable> [ WIT
 
 ALTER USER <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET ALL
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET ALL
 
 <phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
 
     <replaceable class="parameter">role_name</replaceable>
   | CURRENT_USER
   | SESSION_USER
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index d02179f..d978789 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -74,7 +74,7 @@ COMMENT ON
 
 <phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
 
-    object_name
+    <replaceable class="parameter">database_name</replaceable>
   | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 475c85b..fac722f 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -39,9 +39,14 @@ GRANT { { USAGE | SELECT | UPDATE }
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
 
 GRANT { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
-    ON DATABASE <replaceable>database_name</replaceable> [, ...]
+    ON DATABASE <replaceable>database_specification</replaceable> [, ...]
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
 
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
+
 GRANT { USAGE | ALL [ PRIVILEGES ] }
     ON DOMAIN <replaceable>domain_name</replaceable> [, ...]
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index e3e3f2f..c7caaf1 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -46,10 +46,15 @@ REVOKE [ GRANT OPTION FOR ]
 
 REVOKE [ GRANT OPTION FOR ]
     { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
-    ON DATABASE <replaceable>database_name</replaceable> [, ...]
+    ON DATABASE <replaceable>database_specification</replaceable> [, ...]
     FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
     [ CASCADE | RESTRICT ]
 
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
+
 REVOKE [ GRANT OPTION FOR ]
     { USAGE | ALL [ PRIVILEGES ] }
     ON DOMAIN <replaceable>domain_name</replaceable> [, ...]
diff --git a/doc/src/sgml/ref/security_label.sgml b/doc/src/sgml/ref/security_label.sgml
index 3e2391b..050243f 100644
--- a/doc/src/sgml/ref/security_label.sgml
+++ b/doc/src/sgml/ref/security_label.sgml
@@ -52,7 +52,7 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
 
 <phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
 
-    object_name
+    <replaceable class="parameter">database_name</replaceable>
   | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index ccde66a..c1a3e06 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -65,6 +65,7 @@
 #include "foreign/foreign.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
+#include "nodes/parsenodes.h"
 #include "parser/parse_func.h"
 #include "parser/parse_type.h"
 #include "utils/acl.h"
@@ -647,10 +648,10 @@ objectNamesToOids(GrantObjectType objtype, List *objnames)
 		case ACL_OBJECT_DATABASE:
 			foreach(cell, objnames)
 			{
-				char	   *dbname = strVal(lfirst(cell));
+				DbSpec	   *dbspec = lfirst(cell);
 				Oid			dbid;
 
-				dbid = get_database_oid(dbname, false);
+				dbid = get_dbspec_oid(dbspec,false);
 				objects = lappend_oid(objects, dbid);
 			}
 			break;
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index f294135..71cfa13 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -927,9 +927,9 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 	}
 
 	/* look up and lock the database, if specified */
-	if (stmt->database != NULL)
+	if (stmt->dbspec != NULL)
 	{
-		databaseid = get_database_oid(stmt->database, false);
+		databaseid = get_dbspec_oid((DbSpec *)stmt->dbspec,false);
 		shdepLockAndCheckObject(DatabaseRelationId, databaseid);
 
 		if (!stmt->role)
@@ -940,11 +940,11 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 			 */
 			if (!pg_database_ownercheck(databaseid, GetUserId()))
 				aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-							   stmt->database);
+						get_dbspec_name((DbSpec *)stmt->dbspec));
 		}
 	}
 
-	if (!stmt->role && !stmt->database)
+	if (!stmt->role && !stmt->dbspec)
 	{
 		/* Must be superuser to alter settings globally. */
 		if (!superuser())
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 933378a..3c67c45 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -4236,7 +4236,7 @@ _copyAlterRoleSetStmt(const AlterRoleSetStmt *from)
 	AlterRoleSetStmt *newnode = makeNode(AlterRoleSetStmt);
 
 	COPY_NODE_FIELD(role);
-	COPY_STRING_FIELD(database);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(setstmt);
 
 	return newnode;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 3570514..fcdd8fa 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -2051,7 +2051,7 @@ static bool
 _equalAlterRoleSetStmt(const AlterRoleSetStmt *a, const AlterRoleSetStmt *b)
 {
 	COMPARE_NODE_FIELD(role);
-	COMPARE_STRING_FIELD(database);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(setstmt);
 
 	return true;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 431a287..b8a2c73 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -397,7 +397,7 @@ static Node *makeDbSpec(DbSpecType type, int location);
 				transform_element_list transform_type_list
 				TriggerTransitions TriggerReferencing
 				publication_name_list
-				vacuum_relation_list opt_vacuum_relation_list
+				vacuum_relation_list opt_vacuum_relation_list db_spec_name_list
 
 %type <list>	group_by_list
 %type <node>	group_by_item empty_grouping_set rollup_clause cube_clause
@@ -1142,7 +1142,7 @@ AlterRoleStmt:
 
 opt_in_database:
 			   /* EMPTY */					{ $$ = NULL; }
-			| IN_P DATABASE database_name	{ $$ = $3; }
+			| IN_P DATABASE db_spec_name	{ $$ = $3; }
 		;
 
 AlterRoleSetStmt:
@@ -1150,7 +1150,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->database = $4;
+					n->dbspec = (Node *)$4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1158,7 +1158,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = NULL;
-					n->database = $4;
+					n->dbspec = (Node *)$4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1166,7 +1166,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->database = $4;
+					n->dbspec = (Node *)$4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1174,7 +1174,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = NULL;
-					n->database = $4;
+					n->dbspec = (Node *)$4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -6994,7 +6994,7 @@ privilege_target:
 					n->objs = $2;
 					$$ = n;
 				}
-			| DATABASE name_list
+			| DATABASE db_spec_name_list
 				{
 					PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
 					n->targtype = ACL_TARGET_OBJECT;
@@ -14431,6 +14431,13 @@ database_name:
 				}
 		;
 
+db_spec_name_list:	db_spec_name
+					{ $$ = list_make1($1); }
+			| db_spec_name_list ',' db_spec_name
+					{ $$ = lappend($1, $3); }
+		;
+
+
 db_spec_name:
 			ColId
 				{
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 4852c7d..692ad74 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2455,7 +2455,7 @@ typedef struct AlterRoleSetStmt
 {
 	NodeTag		type;
 	RoleSpec   *role;			/* role */
-	char	   *database;		/* database name, or NULL */
+	Node	   *dbspec;			/* name of database to set, DbSpec */
 	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterRoleSetStmt;
 
diff --git a/src/test/regress/expected/publication.out b/src/test/regress/expected/publication.out
index b101331..81d8629 100644
--- a/src/test/regress/expected/publication.out
+++ b/src/test/regress/expected/publication.out
@@ -206,6 +206,17 @@ ALTER PUBLICATION testpub2 ADD TABLE testpub_tbl1;  -- ok
 DROP PUBLICATION testpub2;
 SET ROLE regress_publication_user;
 REVOKE CREATE ON DATABASE regression FROM regress_publication_user2;
+--- test grant on database current_database
+GRANT CREATE ON DATABASE CURRENT_DATABASE TO regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- ok
+DROP PUBLICATION testpub2;
+SET ROLE regress_publication_user;
+REVOKE CREATE ON DATABASE CURRENT_DATABASE FROM regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- fail
+ERROR:  permission denied for database regression
+SET ROLE regress_publication_user;
 DROP TABLE testpub_parted;
 DROP VIEW testpub_view;
 DROP TABLE testpub_tbl1;
diff --git a/src/test/regress/expected/rolenames.out b/src/test/regress/expected/rolenames.out
index dce82f5..ab02155 100644
--- a/src/test/regress/expected/rolenames.out
+++ b/src/test/regress/expected/rolenames.out
@@ -369,6 +369,26 @@ SELECT * FROM chksetconfig();
 ----+------+------------+-----------
 (0 rows)
 
+--  ALTER ROLE IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE SET application_name to 'FOO';
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+     db     |       role       |  rolkeyword  |         setconfig         
+------------+------------------+--------------+---------------------------
+ regression | Public           | -            | {application_name=BARBAR}
+ regression | current_user     | -            | {application_name=FOOFOO}
+ regression | regress_testrol2 | current_user | {application_name=FOO}
+(3 rows)
+
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+ db | role | rolkeyword | setconfig 
+----+------+------------+-----------
+(0 rows)
+
 ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ'; -- error
 ERROR:  syntax error at or near "CURRENT_ROLE"
 LINE 1: ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ';
@@ -421,6 +441,26 @@ SELECT * FROM chksetconfig();
 ----+------+------------+-----------
 (0 rows)
 
+--  ALTER USER IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE SET application_name to 'BAR';
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+     db     |       role       |  rolkeyword  |         setconfig         
+------------+------------------+--------------+---------------------------
+ regression | Public           | -            | {application_name=BARBAR}
+ regression | current_user     | -            | {application_name=FOOFOO}
+ regression | regress_testrol1 | session_user | {application_name=BAR}
+(3 rows)
+
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+ db | role | rolkeyword | setconfig 
+----+------+------------+-----------
+(0 rows)
+
 ALTER USER CURRENT_USER SET application_name to 'BAZ'; -- error
 ALTER USER USER SET application_name to 'BOOM'; -- error
 ERROR:  syntax error at or near "USER"
diff --git a/src/test/regress/sql/publication.sql b/src/test/regress/sql/publication.sql
index 815410b..0ee3fd3 100644
--- a/src/test/regress/sql/publication.sql
+++ b/src/test/regress/sql/publication.sql
@@ -112,6 +112,18 @@ DROP PUBLICATION testpub2;
 SET ROLE regress_publication_user;
 REVOKE CREATE ON DATABASE regression FROM regress_publication_user2;
 
+--- test grant on database current_database
+GRANT CREATE ON DATABASE CURRENT_DATABASE TO regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- ok
+DROP PUBLICATION testpub2;
+
+SET ROLE regress_publication_user;
+REVOKE CREATE ON DATABASE CURRENT_DATABASE FROM regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- fail
+SET ROLE regress_publication_user;
+
 DROP TABLE testpub_parted;
 DROP VIEW testpub_view;
 DROP TABLE testpub_tbl1;
diff --git a/src/test/regress/sql/rolenames.sql b/src/test/regress/sql/rolenames.sql
index 4c5706b..ff11931 100644
--- a/src/test/regress/sql/rolenames.sql
+++ b/src/test/regress/sql/rolenames.sql
@@ -146,6 +146,15 @@ ALTER ROLE "Public" RESET application_name;
 ALTER ROLE ALL RESET application_name;
 SELECT * FROM chksetconfig();
 
+--  ALTER ROLE IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE SET application_name to 'FOO';
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
 
 ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ'; -- error
 ALTER ROLE USER SET application_name to 'BOOM'; -- error
@@ -170,6 +179,16 @@ ALTER USER ALL RESET application_name;
 SELECT * FROM chksetconfig();
 
 
+--  ALTER USER IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE SET application_name to 'BAR';
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+
 ALTER USER CURRENT_USER SET application_name to 'BAZ'; -- error
 ALTER USER USER SET application_name to 'BOOM'; -- error
 ALTER USER PUBLIC SET application_name to 'BOMB'; -- error

diff --git a/doc/src/sgml/ref/alter_database.sgml b/doc/src/sgml/ref/alter_database.sgml
index 7db878c..3c56d90 100644
--- a/doc/src/sgml/ref/alter_database.sgml
+++ b/doc/src/sgml/ref/alter_database.sgml
@@ -31,14 +31,14 @@ ALTER DATABASE <replaceable class="parameter">name</replaceable> [ [ WITH ] <rep
 
 ALTER DATABASE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER DATABASE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
 
 ALTER DATABASE <replaceable class="parameter">name</replaceable> SET TABLESPACE <replaceable class="parameter">new_tablespace</replaceable>
 
-ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET <replaceable>configuration_parameter</replaceable>
-ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET ALL
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> RESET <replaceable>configuration_parameter</replaceable>
+ALTER DATABASE <replaceable class="parameter">{name | CURRENT_DATABASE}</replaceable> RESET ALL
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/alter_role.sgml b/doc/src/sgml/ref/alter_role.sgml
index 573a3e8..cf7b575 100644
--- a/doc/src/sgml/ref/alter_role.sgml
+++ b/doc/src/sgml/ref/alter_role.sgml
@@ -38,16 +38,21 @@ ALTER ROLE <replaceable class="parameter">role_specification</replaceable> [ WIT
 
 ALTER ROLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET ALL
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET ALL
 
 <phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
 
     <replaceable class="parameter">role_name</replaceable>
   | CURRENT_USER
   | SESSION_USER
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/alter_user.sgml b/doc/src/sgml/ref/alter_user.sgml
index 8f50f43..cbf8163 100644
--- a/doc/src/sgml/ref/alter_user.sgml
+++ b/doc/src/sgml/ref/alter_user.sgml
@@ -38,16 +38,21 @@ ALTER USER <replaceable class="parameter">role_specification</replaceable> [ WIT
 
 ALTER USER <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET ALL
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET ALL
 
 <phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
 
     <replaceable class="parameter">role_name</replaceable>
   | CURRENT_USER
   | SESSION_USER
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 965c5a4..025b672 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -31,7 +31,7 @@ COMMENT ON
   CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
   CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ON DOMAIN <replaceable class="parameter">domain_name</replaceable> |
   CONVERSION <replaceable class="parameter">object_name</replaceable> |
-  DATABASE <replaceable class="parameter">object_name</replaceable> |
+  DATABASE <replaceable class="parameter">database_specification</replaceable> |
   DOMAIN <replaceable class="parameter">object_name</replaceable> |
   EXTENSION <replaceable class="parameter">object_name</replaceable> |
   EVENT TRIGGER <replaceable class="parameter">object_name</replaceable> |
@@ -73,6 +73,11 @@ COMMENT ON
 * |
 [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] |
 [ [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] ] ORDER BY [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ]
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
@@ -315,6 +320,7 @@ COMMENT ON CONVERSION my_conv IS 'Conversion to UTF8';
 COMMENT ON CONSTRAINT bar_col_cons ON bar IS 'Constrains column col';
 COMMENT ON CONSTRAINT dom_col_constr ON DOMAIN dom IS 'Constrains col of domain';
 COMMENT ON DATABASE my_database IS 'Development Database';
+COMMENT ON DATABASE current_database IS 'Comment on current Database';
 COMMENT ON DOMAIN my_domain IS 'Email Address Domain';
 COMMENT ON EXTENSION hstore IS 'implements the hstore data type';
 COMMENT ON FOREIGN DATA WRAPPER mywrapper IS 'my foreign data wrapper';
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index ff64c7a..880a30d 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -39,9 +39,14 @@ GRANT { { USAGE | SELECT | UPDATE }
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
 
 GRANT { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
-    ON DATABASE <replaceable>database_name</replaceable> [, ...]
+    ON DATABASE <replaceable>database_specification</replaceable> [, ...]
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
 
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
+
 GRANT { USAGE | ALL [ PRIVILEGES ] }
     ON DOMAIN <replaceable>domain_name</replaceable> [, ...]
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 7018202..f7a3055 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -46,10 +46,15 @@ REVOKE [ GRANT OPTION FOR ]
 
 REVOKE [ GRANT OPTION FOR ]
     { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
-    ON DATABASE <replaceable>database_name</replaceable> [, ...]
+    ON DATABASE <replaceable>database_specification</replaceable> [, ...]
     FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
     [ CASCADE | RESTRICT ]
 
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
+
 REVOKE [ GRANT OPTION FOR ]
     { USAGE | ALL [ PRIVILEGES ] }
     ON DOMAIN <replaceable>domain_name</replaceable> [, ...]
diff --git a/doc/src/sgml/ref/security_label.sgml b/doc/src/sgml/ref/security_label.sgml
index e9cfdec..c582c96 100644
--- a/doc/src/sgml/ref/security_label.sgml
+++ b/doc/src/sgml/ref/security_label.sgml
@@ -26,7 +26,7 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
   TABLE <replaceable class="parameter">object_name</replaceable> |
   COLUMN <replaceable class="parameter">table_name</replaceable>.<replaceable class="parameter">column_name</replaceable> |
   AGGREGATE <replaceable class="parameter">aggregate_name</replaceable> ( <replaceable>aggregate_signature</replaceable> ) |
-  DATABASE <replaceable class="parameter">object_name</replaceable> |
+  DATABASE <replaceable class="parameter">database_specification</replaceable> |
   DOMAIN <replaceable class="parameter">object_name</replaceable> |
   EVENT TRIGGER <replaceable class="parameter">object_name</replaceable> |
   FOREIGN TABLE <replaceable class="parameter">object_name</replaceable>
@@ -51,6 +51,11 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
 * |
 [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] |
 [ [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] ] ORDER BY [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ]
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index e481cf3..5d71fdf 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -65,6 +65,7 @@
 #include "foreign/foreign.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
+#include "nodes/parsenodes.h"
 #include "parser/parse_func.h"
 #include "parser/parse_type.h"
 #include "utils/acl.h"
@@ -657,10 +658,10 @@ objectNamesToOids(GrantObjectType objtype, List *objnames)
 		case ACL_OBJECT_DATABASE:
 			foreach(cell, objnames)
 			{
-				char	   *dbname = strVal(lfirst(cell));
+				DbSpec	   *dbspec = lfirst(cell);
 				Oid			dbid;
 
-				dbid = get_database_oid(dbname, false);
+				dbid = get_dbspec_oid(dbspec,false);
 				objects = lappend_oid(objects, dbid);
 			}
 			break;
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index 9553675..8bdc315 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -724,7 +724,6 @@ const ObjectAddress InvalidObjectAddress =
 	InvalidOid,
 	0
 };
-
 static ObjectAddress get_object_address_unqualified(ObjectType objtype,
 							   Value *strval, bool missing_ok);
 static ObjectAddress get_relation_by_qualified_name(ObjectType objtype,
@@ -868,6 +867,10 @@ get_object_address(ObjectType objtype, Node *object,
 				}
 				break;
 			case OBJECT_DATABASE:
+				address.classId = DatabaseRelationId;
+				address.objectId = get_dbspec_oid((DbSpec *)object, missing_ok);
+				address.objectSubId = 0;
+				break;
 			case OBJECT_EXTENSION:
 			case OBJECT_TABLESPACE:
 			case OBJECT_ROLE:
@@ -2247,7 +2250,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
 		case OBJECT_DATABASE:
 			if (!pg_database_ownercheck(address.objectId, roleid))
 				aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-							   strVal((Value *) object));
+							   get_dbspec_name((DbSpec *)object));
 			break;
 		case OBJECT_TYPE:
 		case OBJECT_DOMAIN:
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 21e3f1e..2999ae9 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -806,7 +806,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
 	switch (stmt->objectType)
 	{
 		case OBJECT_DATABASE:
-			return AlterDatabaseOwner(strVal((Value *) stmt->object), newowner);
+			return AlterDatabaseOwner((DbSpec *) stmt->object, newowner);
 
 		case OBJECT_SCHEMA:
 			return AlterSchemaOwner(strVal((Value *) stmt->object), newowner);
diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c
index 2dc9371..047d283 100644
--- a/src/backend/commands/comment.c
+++ b/src/backend/commands/comment.c
@@ -52,13 +52,15 @@ CommentObject(CommentStmt *stmt)
 	 */
 	if (stmt->objtype == OBJECT_DATABASE)
 	{
-		char	   *database = strVal((Value *) stmt->object);
-
-		if (!OidIsValid(get_database_oid(database, true)))
+		if (!OidIsValid(get_dbspec_oid((DbSpec *)stmt->object, true)))
 		{
+			char		*dbname = NULL;
+
+			dbname = get_dbspec_name((DbSpec *)stmt->object);
+
 			ereport(WARNING,
 					(errcode(ERRCODE_UNDEFINED_DATABASE),
-					 errmsg("database \"%s\" does not exist", database)));
+					 errmsg("database \"%s\" does not exist", dbname)));
 			return address;
 		}
 	}
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index eb1a469..600b592 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -1413,6 +1413,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	Datum		new_record[Natts_pg_database];
 	bool		new_record_nulls[Natts_pg_database];
 	bool		new_record_repl[Natts_pg_database];
+	char		*dbname = NULL;
+
+	dbname = get_dbspec_name((DbSpec *)stmt->dbspec);
 
 	/* Extract options from the statement node tree */
 	foreach(option, stmt->options)
@@ -1477,7 +1480,7 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 					 parser_errposition(pstate, dtablespace->location)));
 		/* this case isn't allowed within a transaction block */
 		PreventTransactionChain(isTopLevel, "ALTER DATABASE SET TABLESPACE");
-		movedb(stmt->dbname, defGetString(dtablespace));
+		movedb(dbname, defGetString(dtablespace));
 		return InvalidOid;
 	}
 
@@ -1503,20 +1506,20 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	ScanKeyInit(&scankey,
 				Anum_pg_database_datname,
 				BTEqualStrategyNumber, F_NAMEEQ,
-				CStringGetDatum(stmt->dbname));
+				CStringGetDatum(dbname));
 	scan = systable_beginscan(rel, DatabaseNameIndexId, true,
 							  NULL, 1, &scankey);
 	tuple = systable_getnext(scan);
 	if (!HeapTupleIsValid(tuple))
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_DATABASE),
-				 errmsg("database \"%s\" does not exist", stmt->dbname)));
+				 errmsg("database \"%s\" does not exist", dbname)));
 
 	dboid = HeapTupleGetOid(tuple);
 
 	if (!pg_database_ownercheck(HeapTupleGetOid(tuple), GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-					   stmt->dbname);
+					   dbname);
 
 	/*
 	 * In order to avoid getting locked out and having to go through
@@ -1574,7 +1577,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 Oid
 AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 {
-	Oid			datid = get_database_oid(stmt->dbname, false);
+	Oid			datid;
+
+	datid = get_dbspec_oid((DbSpec *)stmt->dbspec, false);
 
 	/*
 	 * Obtain a lock on the database and make sure it didn't go away in the
@@ -1584,7 +1589,7 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 
 	if (!pg_database_ownercheck(datid, GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-					   stmt->dbname);
+				get_dbspec_name((DbSpec *)stmt->dbspec));
 
 	AlterSetting(datid, InvalidOid, stmt->setstmt);
 
@@ -1598,7 +1603,7 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
  * ALTER DATABASE name OWNER TO newowner
  */
 ObjectAddress
-AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
+AlterDatabaseOwner(const DbSpec *dbspec, Oid newOwnerId)
 {
 	Oid			db_id;
 	HeapTuple	tuple;
@@ -1607,6 +1612,9 @@ AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
 	SysScanDesc scan;
 	Form_pg_database datForm;
 	ObjectAddress address;
+	char		*dbname;
+
+	dbname = get_dbspec_name(dbspec);
 
 	/*
 	 * Get the old tuple.  We don't need a lock on the database per se,
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index f294135..71cfa13 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -927,9 +927,9 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 	}
 
 	/* look up and lock the database, if specified */
-	if (stmt->database != NULL)
+	if (stmt->dbspec != NULL)
 	{
-		databaseid = get_database_oid(stmt->database, false);
+		databaseid = get_dbspec_oid((DbSpec *)stmt->dbspec,false);
 		shdepLockAndCheckObject(DatabaseRelationId, databaseid);
 
 		if (!stmt->role)
@@ -940,11 +940,11 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 			 */
 			if (!pg_database_ownercheck(databaseid, GetUserId()))
 				aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-							   stmt->database);
+						get_dbspec_name((DbSpec *)stmt->dbspec));
 		}
 	}
 
-	if (!stmt->role && !stmt->database)
+	if (!stmt->role && !stmt->dbspec)
 	{
 		/* Must be superuser to alter settings globally. */
 		if (!superuser())
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 6c4612d..7172125 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -2043,6 +2043,7 @@ ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op)
 			*op->resnull = fcinfo.isnull;
 			break;
 		case SVFOP_CURRENT_CATALOG:
+		case SVFOP_CURRENT_DATABASE:
 			InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
 			*op->resvalue = current_database(&fcinfo);
 			*op->resnull = fcinfo.isnull;
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index aff9a62..0a9d588 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2922,6 +2922,18 @@ _copyTriggerTransition(const TriggerTransition *from)
 	return newnode;
 }
 
+static DbSpec *
+_copyDatabaseSpec(const DbSpec *from)
+{
+	DbSpec   *newnode = makeNode(DbSpec);
+
+	COPY_SCALAR_FIELD(dbtype);
+	COPY_STRING_FIELD(dbname);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
 static Query *
 _copyQuery(const Query *from)
 {
@@ -3746,7 +3758,7 @@ _copyAlterDatabaseStmt(const AlterDatabaseStmt *from)
 {
 	AlterDatabaseStmt *newnode = makeNode(AlterDatabaseStmt);
 
-	COPY_STRING_FIELD(dbname);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(options);
 
 	return newnode;
@@ -3757,7 +3769,7 @@ _copyAlterDatabaseSetStmt(const AlterDatabaseSetStmt *from)
 {
 	AlterDatabaseSetStmt *newnode = makeNode(AlterDatabaseSetStmt);
 
-	COPY_STRING_FIELD(dbname);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(setstmt);
 
 	return newnode;
@@ -4236,7 +4248,7 @@ _copyAlterRoleSetStmt(const AlterRoleSetStmt *from)
 	AlterRoleSetStmt *newnode = makeNode(AlterRoleSetStmt);
 
 	COPY_NODE_FIELD(role);
-	COPY_STRING_FIELD(database);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(setstmt);
 
 	return newnode;
@@ -5563,7 +5575,9 @@ copyObjectImpl(const void *from)
 		case T_PartitionCmd:
 			retval = _copyPartitionCmd(from);
 			break;
-
+		case T_DbSpec:
+			retval = _copyDatabaseSpec(from);
+			break;
 			/*
 			 * MISCELLANEOUS NODES
 			 */
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 2e869a9..c73f682 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1645,7 +1645,7 @@ _equalCreatedbStmt(const CreatedbStmt *a, const CreatedbStmt *b)
 static bool
 _equalAlterDatabaseStmt(const AlterDatabaseStmt *a, const AlterDatabaseStmt *b)
 {
-	COMPARE_STRING_FIELD(dbname);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(options);
 
 	return true;
@@ -1654,7 +1654,7 @@ _equalAlterDatabaseStmt(const AlterDatabaseStmt *a, const AlterDatabaseStmt *b)
 static bool
 _equalAlterDatabaseSetStmt(const AlterDatabaseSetStmt *a, const AlterDatabaseSetStmt *b)
 {
-	COMPARE_STRING_FIELD(dbname);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(setstmt);
 
 	return true;
@@ -2061,7 +2061,7 @@ static bool
 _equalAlterRoleSetStmt(const AlterRoleSetStmt *a, const AlterRoleSetStmt *b)
 {
 	COMPARE_NODE_FIELD(role);
-	COMPARE_STRING_FIELD(database);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(setstmt);
 
 	return true;
@@ -2887,6 +2887,16 @@ _equalPartitionCmd(const PartitionCmd *a, const PartitionCmd *b)
 	return true;
 }
 
+static bool
+_equalDatabaseSpec(const DbSpec *a, const DbSpec *b)
+{
+	COMPARE_SCALAR_FIELD(dbtype);
+	COMPARE_STRING_FIELD(dbname);
+	COMPARE_LOCATION_FIELD(location);
+
+	return true;
+}
+
 /*
  * Stuff from pg_list.h
  */
@@ -3703,6 +3713,9 @@ equal(const void *a, const void *b)
 		case T_PartitionCmd:
 			retval = _equalPartitionCmd(a, b);
 			break;
+		case T_DbSpec:
+			retval = _equalDatabaseSpec(a, b);
+			break;
 
 		default:
 			elog(ERROR, "unrecognized node type: %d",
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index ebfc94f..224ee1b 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -187,7 +187,7 @@ static void processCASbits(int cas_bits, int location, const char *constrType,
 			   bool *deferrable, bool *initdeferred, bool *not_valid,
 			   bool *no_inherit, core_yyscan_t yyscanner);
 static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
-
+static Node *makeDbSpec(DbSpecType type, int location);
 %}
 
 %pure-parser
@@ -397,7 +397,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				transform_element_list transform_type_list
 				TriggerTransitions TriggerReferencing
 				publication_name_list
-				vacuum_relation_list opt_vacuum_relation_list
+				vacuum_relation_list opt_vacuum_relation_list db_spec_name_list
 
 %type <list>	group_by_list
 %type <node>	group_by_item empty_grouping_set rollup_clause cube_clause
@@ -572,6 +572,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				opt_frame_clause frame_extent frame_bound
 %type <str>		opt_existing_window_name
 %type <boolean> opt_if_not_exists
+%type <node>	db_spec_name
 %type <ival>	generated_when override_kind
 %type <partspec>	PartitionSpec OptPartitionSpec
 %type <str>			part_strategy
@@ -617,7 +618,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	COMMITTED CONCURRENTLY CONFIGURATION CONFLICT CONNECTION CONSTRAINT
 	CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE
 	CROSS CSV CUBE CURRENT_P
-	CURRENT_CATALOG CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
+	CURRENT_CATALOG CURRENT_DATABASE CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
 
 	DATA_P DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
@@ -1156,7 +1157,7 @@ AlterRoleStmt:
 
 opt_in_database:
 			   /* EMPTY */					{ $$ = NULL; }
-			| IN_P DATABASE database_name	{ $$ = $3; }
+			| IN_P DATABASE db_spec_name	{ $$ = $3; }
 		;
 
 AlterRoleSetStmt:
@@ -1164,7 +1165,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->database = $4;
+					n->dbspec = (Node *)$4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1172,7 +1173,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = NULL;
-					n->database = $4;
+					n->dbspec = (Node *)$4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1180,7 +1181,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->database = $4;
+					n->dbspec = (Node *)$4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1188,7 +1189,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = NULL;
-					n->database = $4;
+					n->dbspec = (Node *)$4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -6400,6 +6401,14 @@ CommentStmt:
 					n->comment = $6;
 					$$ = (Node *) n;
 				}
+			| COMMENT ON DATABASE db_spec_name IS comment_text
+				{
+					CommentStmt *n = makeNode(CommentStmt);
+					n->objtype = OBJECT_DATABASE;
+					n->object = (Node *) $4;
+					n->comment = $6;
+					$$ = (Node *) n;
+				}
 			| COMMENT ON TYPE_P Typename IS comment_text
 				{
 					CommentStmt *n = makeNode(CommentStmt);
@@ -6564,7 +6573,6 @@ comment_type_any_name:
 /* object types taking name */
 comment_type_name:
 			ACCESS METHOD						{ $$ = OBJECT_ACCESS_METHOD; }
-			| DATABASE							{ $$ = OBJECT_DATABASE; }
 			| EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
 			| EXTENSION							{ $$ = OBJECT_EXTENSION; }
 			| FOREIGN DATA_P WRAPPER			{ $$ = OBJECT_FDW; }
@@ -6613,6 +6621,16 @@ SecLabelStmt:
 					n->label = $8;
 					$$ = (Node *) n;
 				}
+			| SECURITY LABEL opt_provider ON DATABASE db_spec_name
+			IS security_label
+				{
+					SecLabelStmt *n = makeNode(SecLabelStmt);
+					n->provider = $3;
+					n->objtype = OBJECT_DATABASE;
+					n->object = (Node *) $6;
+					n->label = $8;
+					$$ = (Node *) n;
+				}
 			| SECURITY LABEL opt_provider ON TYPE_P Typename
 			  IS security_label
 				{
@@ -6701,8 +6719,7 @@ security_label_type_any_name:
 
 /* object types taking name */
 security_label_type_name:
-			DATABASE							{ $$ = OBJECT_DATABASE; }
-			| EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
+			EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
 			| opt_procedural LANGUAGE			{ $$ = OBJECT_LANGUAGE; }
 			| PUBLICATION						{ $$ = OBJECT_PUBLICATION; }
 			| ROLE								{ $$ = OBJECT_ROLE; }
@@ -7062,7 +7079,7 @@ privilege_target:
 					n->objs = $2;
 					$$ = n;
 				}
-			| DATABASE name_list
+			| DATABASE db_spec_name_list
 				{
 					PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
 					n->targtype = ACL_TARGET_OBJECT;
@@ -9287,11 +9304,11 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
 					n->newowner = $6;
 					$$ = (Node *)n;
 				}
-			| ALTER DATABASE database_name OWNER TO RoleSpec
+			| ALTER DATABASE db_spec_name OWNER TO RoleSpec
 				{
 					AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
 					n->objectType = OBJECT_DATABASE;
-					n->object = (Node *) makeString($3);
+					n->object = (Node *) $3;
 					n->newowner = $6;
 					$$ = (Node *)n;
 				}
@@ -10113,24 +10130,24 @@ opt_equal:	'='										{}
  *****************************************************************************/
 
 AlterDatabaseStmt:
-			ALTER DATABASE database_name WITH createdb_opt_list
+			ALTER DATABASE db_spec_name WITH createdb_opt_list
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = $5;
 					$$ = (Node *)n;
 				 }
-			| ALTER DATABASE database_name createdb_opt_list
+			| ALTER DATABASE db_spec_name createdb_opt_list
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = $4;
 					$$ = (Node *)n;
 				 }
-			| ALTER DATABASE database_name SET TABLESPACE name
+			| ALTER DATABASE db_spec_name SET TABLESPACE name
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = list_make1(makeDefElem("tablespace",
 														(Node *)makeString($6), @6));
 					$$ = (Node *)n;
@@ -10138,10 +10155,10 @@ AlterDatabaseStmt:
 		;
 
 AlterDatabaseSetStmt:
-			ALTER DATABASE database_name SetResetClause
+			ALTER DATABASE db_spec_name SetResetClause
 				{
 					AlterDatabaseSetStmt *n = makeNode(AlterDatabaseSetStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->setstmt = $4;
 					$$ = (Node *)n;
 				}
@@ -13670,6 +13687,10 @@ func_expr_common_subexpr:
 				{
 					$$ = makeSQLValueFunction(SVFOP_SESSION_USER, -1, @1);
 				}
+			| CURRENT_DATABASE
+				{
+					$$ = makeSQLValueFunction(SVFOP_CURRENT_DATABASE, -1, @1);
+				}
 			| USER
 				{
 					$$ = makeSQLValueFunction(SVFOP_USER, -1, @1);
@@ -14640,7 +14661,36 @@ name_list:	name
 name:		ColId									{ $$ = $1; };
 
 database_name:
-			ColId									{ $$ = $1; };
+			ColId									{ $$ = $1; }
+			| CURRENT_DATABASE
+				{
+					ereport(ERROR,
+							(errcode(ERRCODE_RESERVED_NAME),
+							 errmsg("%s cannot be used as a database name here",
+									"CURRENT_DATABASE"),
+							 parser_errposition(@1)));
+				}
+		;
+
+db_spec_name_list:	db_spec_name
+					{ $$ = list_make1($1); }
+			| db_spec_name_list ',' db_spec_name
+					{ $$ = lappend($1, $3); }
+		;
+
+
+db_spec_name:
+			ColId
+				{
+					DbSpec *n = (DbSpec *) makeDbSpec(DBSPEC_CSTRING, @1);
+					n->dbname = pstrdup($1);
+					$$ = (Node *)n;
+				}
+			| CURRENT_DATABASE
+				{
+					$$ = (Node *) makeDbSpec(DBSPEC_CURRENT_DATABASE, @1);
+				}
+		;
 
 access_method:
 			ColId									{ $$ = $1; };
@@ -14666,6 +14716,8 @@ func_name:	type_function_name
 						$$ = check_func_name(lcons(makeString($1), $2),
 											 yyscanner);
 					}
+			| CURRENT_DATABASE
+					{ $$ = list_make1(makeString("current_database")); }
 		;
 
 
@@ -15321,6 +15373,7 @@ reserved_keyword:
 			| CONSTRAINT
 			| CREATE
 			| CURRENT_CATALOG
+			| CURRENT_DATABASE
 			| CURRENT_DATE
 			| CURRENT_ROLE
 			| CURRENT_TIME
@@ -16232,6 +16285,20 @@ makeRecursiveViewSelect(char *relname, List *aliases, Node *query)
 	return (Node *) s;
 }
 
+/* makeDbSpec
+ * Create a DbSpec with the given type
+ */
+static Node *
+makeDbSpec(DbSpecType type, int location)
+{
+	DbSpec *spec = makeNode(DbSpec);
+
+	spec->dbtype = type;
+	spec->location = location;
+
+	return (Node *) spec;
+}
+
 /* parser_init()
  * Initialize to parse one query string
  */
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 29f9da7..226a15b 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -2334,6 +2334,7 @@ transformSQLValueFunction(ParseState *pstate, SQLValueFunction *svf)
 		case SVFOP_SESSION_USER:
 		case SVFOP_CURRENT_CATALOG:
 		case SVFOP_CURRENT_SCHEMA:
+		case SVFOP_CURRENT_DATABASE:
 			svf->type = NAMEOID;
 			break;
 	}
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 21593b2..508fd41 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1882,6 +1882,9 @@ FigureColnameInternal(Node *node, char **name)
 				case SVFOP_CURRENT_SCHEMA:
 					*name = "current_schema";
 					return 2;
+				case SVFOP_CURRENT_DATABASE:
+					*name = "current_database";
+					return 2;
 			}
 			break;
 		case T_XmlExpr:
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 2f2758f..498cc4d 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -24,6 +24,7 @@
 #include "catalog/pg_auth_members.h"
 #include "catalog/pg_type.h"
 #include "catalog/pg_class.h"
+#include "catalog/pg_database.h"
 #include "commands/dbcommands.h"
 #include "commands/proclang.h"
 #include "commands/tablespace.h"
@@ -5273,3 +5274,66 @@ check_rolespec_name(const RoleSpec *role, const char *detail_msg)
 							role->rolename)));
 	}
 }
+
+
+/*
+ * Given a DbSpec, returns a palloc'ed copy of the corresponding role's name.
+ */
+char *
+get_dbspec_name(const DbSpec *db)
+{
+	char	   *dbname;
+	HeapTuple	tuple;
+	Form_pg_database dbForm;
+
+	switch (db->dbtype)
+	{
+		case DBSPEC_CSTRING:
+			Assert(db->dbname);
+			dbname = db->dbname;
+			break;
+
+		case DBSPEC_CURRENT_DATABASE:
+			tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
+			if (!HeapTupleIsValid(tuple))
+				elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
+
+			dbForm = (Form_pg_database) GETSTRUCT(tuple);
+			dbname = pstrdup(NameStr(dbForm->datname));
+			ReleaseSysCache(tuple);
+			break;
+
+		default:
+			elog(ERROR, "unexpected database type %d", db->dbtype);
+	}
+
+
+	return dbname;
+}
+
+/*
+ * Given a DbSpec node, return the OID it corresponds to.  If missing_ok is
+ * true, return InvalidOid if the database does not exist.
+ */
+Oid
+get_dbspec_oid(const DbSpec *db, bool missing_ok)
+{
+	Oid			oid;
+
+	switch (db->dbtype)
+	{
+		case DBSPEC_CSTRING:
+			Assert(db->dbname);
+			oid = get_database_oid(db->dbname, missing_ok);
+			break;
+
+		case DBSPEC_CURRENT_DATABASE:
+			oid = MyDatabaseId;
+			break;
+
+		default:
+			elog(ERROR, "unexpected database type %d", db->dbtype);
+	}
+
+	return oid;
+}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 8514c21..560f3ff 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8357,6 +8357,10 @@ get_rule_expr(Node *node, deparse_context *context,
 					case SVFOP_CURRENT_SCHEMA:
 						appendStringInfoString(buf, "CURRENT_SCHEMA");
 						break;
+					case SVFOP_CURRENT_DATABASE:
+						appendStringInfoString(buf, "CURRENT_DATABASE");
+						break;
+
 				}
 			}
 			break;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 12290a1..a48f04b 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -673,6 +673,7 @@ emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
 		appendPQExpBuffer(buffer,
 						  "SECURITY LABEL FOR %s ON %s",
 						  fmtId(provider), target);
+
 		appendPQExpBuffer(buffer,
 						  " %s IS ",
 						  fmtId(objname));
@@ -682,6 +683,40 @@ emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
 }
 
 /*
+ * emitDatabaseSecLabels
+ *
+ * Format security label data on database.
+ */
+void
+emitDatabaseSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
+				const char *objname, bool current_datbase)
+{
+	int			i;
+
+	for (i = 0; i < PQntuples(res); i++)
+	{
+		char	   *provider = PQgetvalue(res, i, 0);
+		char	   *label = PQgetvalue(res, i, 1);
+
+		/* must use fmtId result before calling it again */
+		appendPQExpBuffer(buffer,
+						  "SECURITY LABEL FOR %s ON DATABASE",
+						  fmtId(provider));
+
+		if(current_datbase)
+			appendPQExpBuffer(buffer," CURRENT_DATABASE IS ");
+		else
+		{
+			appendPQExpBuffer(buffer,
+							  " %s IS ",
+							  fmtId(objname));
+		}
+		appendStringLiteralConn(buffer, label, conn);
+		appendPQExpBufferStr(buffer, ";\n");
+	}
+}
+
+/*
  * buildACLQueries
  *
  * Build the subqueries to extract out the correct set of ACLs to be
diff --git a/src/bin/pg_dump/dumputils.h b/src/bin/pg_dump/dumputils.h
index fe364dd..cee625b 100644
--- a/src/bin/pg_dump/dumputils.h
+++ b/src/bin/pg_dump/dumputils.h
@@ -49,8 +49,10 @@ extern bool buildDefaultACLCommands(const char *type, const char *nspname,
 extern void buildShSecLabelQuery(PGconn *conn, const char *catalog_name,
 					 uint32 objectId, PQExpBuffer sql);
 extern void emitShSecLabels(PGconn *conn, PGresult *res,
-				PQExpBuffer buffer, const char *target, const char *objname);
-
+				PQExpBuffer buffer, const char *target,
+				const char *objname);
+extern void emitDatabaseSecLabels(PGconn *conn, PGresult *res,
+				PQExpBuffer buffer, const char *objname, bool current_datbase);
 extern void buildACLQueries(PQExpBuffer acl_subquery, PQExpBuffer racl_subquery,
 				PQExpBuffer init_acl_subquery, PQExpBuffer init_racl_subquery,
 				const char *acl_column, const char *acl_owner,
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index e6701aa..e00c89d 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -2803,7 +2803,10 @@ dumpDatabase(Archive *fout)
 			 * Generates warning when loaded into a differently-named
 			 * database.
 			 */
-			appendPQExpBuffer(dbQry, "COMMENT ON DATABASE %s IS ", fmtId(datname));
+			if (fout->remoteVersion >= 110000)
+				appendPQExpBuffer(dbQry, "COMMENT ON DATABASE CURRENT_DATABASE IS ");
+			else
+				appendPQExpBuffer(dbQry, "COMMENT ON DATABASE %s IS ", fmtId(datname));
 			appendStringLiteralAH(dbQry, comment, fout);
 			appendPQExpBufferStr(dbQry, ";\n");
 
@@ -2832,7 +2835,10 @@ dumpDatabase(Archive *fout)
 		buildShSecLabelQuery(conn, "pg_database", dbCatId.oid, seclabelQry);
 		shres = ExecuteSqlQuery(fout, seclabelQry->data, PGRES_TUPLES_OK);
 		resetPQExpBuffer(seclabelQry);
-		emitShSecLabels(conn, shres, seclabelQry, "DATABASE", datname);
+		if (fout->remoteVersion >= 110000)
+			emitDatabaseSecLabels(conn, shres, seclabelQry, datname, true);
+		else
+			emitDatabaseSecLabels(conn, shres, seclabelQry, datname, false);
 		if (strlen(seclabelQry->data))
 			ArchiveEntry(fout, dbCatId, createDumpId(), datname, NULL, NULL,
 						 dba, false, "SECURITY LABEL", SECTION_NONE,
@@ -14788,9 +14794,17 @@ dumpSecLabel(Archive *fout, const char *target,
 		if (labels[i].objsubid != subid)
 			continue;
 
-		appendPQExpBuffer(query,
-						  "SECURITY LABEL FOR %s ON %s IS ",
-						  fmtId(labels[i].provider), target);
+		if (fout->remoteVersion >= 110000 && (strncmp(target, "DATABASE", 8) != 0))
+		{
+			appendPQExpBuffer(query,
+							  "SECURITY LABEL FOR %s ON DATABASE CURRENT_DATABASE IS ",
+							  fmtId(labels[i].provider));
+		}
+		else
+			appendPQExpBuffer(query,
+							  "SECURITY LABEL FOR %s ON %s IS ",
+							  fmtId(labels[i].provider), target);
+
 		appendStringLiteralAH(query, labels[i].label, fout);
 		appendPQExpBufferStr(query, ";\n");
 	}
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index f42c8cd..9221b54 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -24,7 +24,8 @@ extern void dropdb(const char *dbname, bool missing_ok);
 extern ObjectAddress RenameDatabase(const char *oldname, const char *newname);
 extern Oid	AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel);
 extern Oid	AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
-extern ObjectAddress AlterDatabaseOwner(const char *dbname, Oid newOwnerId);
+extern ObjectAddress AlterDatabaseOwner(const DbSpec *dbspec, Oid newOwnerId);
+
 
 extern Oid	get_database_oid(const char *dbname, bool missingok);
 extern char *get_database_name(Oid dbid);
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index c5b5115..d48ed0c 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -464,6 +464,7 @@ typedef enum NodeTag
 	T_OnConflictClause,
 	T_CommonTableExpr,
 	T_RoleSpec,
+	T_DbSpec,
 	T_TriggerTransition,
 	T_PartitionElem,
 	T_PartitionSpec,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 2eaa6b2..217301b 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2459,7 +2459,7 @@ typedef struct AlterRoleSetStmt
 {
 	NodeTag		type;
 	RoleSpec   *role;			/* role */
-	char	   *database;		/* database name, or NULL */
+	Node	   *dbspec;			/* name of database to set, DbSpec */
 	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterRoleSetStmt;
 
@@ -3039,6 +3039,24 @@ typedef struct LoadStmt
 	char	   *filename;		/* file to load */
 } LoadStmt;
 
+
+/*
+ * DbSpecType - The type of a database name.
+ */
+typedef enum DbSpecType
+{
+	DBSPEC_CSTRING,				/* database name is stored as a C string */
+	DBSPEC_CURRENT_DATABASE		/* database name is CURRENT_DATABASE */
+} DbSpecType;
+
+typedef struct DbSpec
+{
+	NodeTag			type;
+	DbSpecType		dbtype;			/* Type of the database */
+	char			*dbname;		/* filled only for DBSPEC_CSTRING */
+	int				location;		/* token location, or -1 if unknown */
+} DbSpec;
+
 /* ----------------------
  *		Createdb Statement
  * ----------------------
@@ -3057,14 +3075,14 @@ typedef struct CreatedbStmt
 typedef struct AlterDatabaseStmt
 {
 	NodeTag		type;
-	char	   *dbname;			/* name of database to alter */
-	List	   *options;		/* List of DefElem nodes */
+	Node		*dbspec;		/* name of database to alter, DbSpec */
+	List	   	*options;		/* List of DefElem nodes */
 } AlterDatabaseStmt;
 
 typedef struct AlterDatabaseSetStmt
 {
 	NodeTag		type;
-	char	   *dbname;			/* database name */
+	Node		*dbspec;			/* DbSpec */
 	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterDatabaseSetStmt;
 
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 074ae0a..c65a05c 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1102,7 +1102,8 @@ typedef enum SQLValueFunctionOp
 	SVFOP_USER,
 	SVFOP_SESSION_USER,
 	SVFOP_CURRENT_CATALOG,
-	SVFOP_CURRENT_SCHEMA
+	SVFOP_CURRENT_SCHEMA,
+	SVFOP_CURRENT_DATABASE
 } SQLValueFunctionOp;
 
 typedef struct SQLValueFunction
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index a932400..f7d4b9a 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -105,6 +105,7 @@ PG_KEYWORD("csv", CSV, UNRESERVED_KEYWORD)
 PG_KEYWORD("cube", CUBE, UNRESERVED_KEYWORD)
 PG_KEYWORD("current", CURRENT_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("current_catalog", CURRENT_CATALOG, RESERVED_KEYWORD)
+PG_KEYWORD("current_database", CURRENT_DATABASE, RESERVED_KEYWORD)
 PG_KEYWORD("current_date", CURRENT_DATE, RESERVED_KEYWORD)
 PG_KEYWORD("current_role", CURRENT_ROLE, RESERVED_KEYWORD)
 PG_KEYWORD("current_schema", CURRENT_SCHEMA, TYPE_FUNC_NAME_KEYWORD)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 254a811..c9cfa85 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -246,6 +246,8 @@ extern Oid	get_rolespec_oid(const RoleSpec *role, bool missing_ok);
 extern void check_rolespec_name(const RoleSpec *role, const char *detail_msg);
 extern HeapTuple get_rolespec_tuple(const RoleSpec *role);
 extern char *get_rolespec_name(const RoleSpec *role);
+extern char *get_dbspec_name(const DbSpec *db);
+extern Oid  get_dbspec_oid(const DbSpec *db, bool missing_ok);
 
 extern void select_best_grantor(Oid roleId, AclMode privileges,
 					const Acl *acl, Oid ownerId,
diff --git a/src/test/regress/expected/dbname.out b/src/test/regress/expected/dbname.out
new file mode 100644
index 0000000..cac34de
--- /dev/null
+++ b/src/test/regress/expected/dbname.out
@@ -0,0 +1,113 @@
+CREATE ROLE dbuser1 with LOGIN;
+CREATE ROLE dbuser2 with SUPERUSER LOGIN;
+CREATE ROLE dbuser3 with SUPERUSER LOGIN;
+DROP DATABASE IF EXISTS db1;
+NOTICE:  database "db1" does not exist, skipping
+CREATE DATABASE db1 with owner=dbuser1;
+CREATE DATABASE "current_database" with owner=dbuser1;
+CREATE DATABASE current_database with owner=dbuser1;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: CREATE DATABASE current_database with owner=dbuser1;
+                        ^
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       | Description 
+------------------+-------------
+ current_database | 
+ db1              | 
+(2 rows)
+
+\c db1;
+SELECT CURRENT_DATABASE;
+ current_database 
+------------------
+ db1
+(1 row)
+
+COMMENT ON DATABASE current_database IS 'db1';
+COMMENT ON DATABASE "current_database" IS 'db2';
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       | Description 
+------------------+-------------
+ current_database | db2
+ db1              | db1
+(2 rows)
+
+-- test alter owner
+ALTER DATABASE current_database OWNER to dbuser2; 
+ALTER DATABASE "current_database" OWNER to dbuser2;
+SELECT d.datname as "Name",
+       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       |  Owner  | Description 
+------------------+---------+-------------
+ current_database | dbuser2 | db2
+ db1              | dbuser2 | db1
+(2 rows)
+
+-- test alter database tablespace
+ALTER DATABASE current_database SET TABLESPACE pg_default;
+ERROR:  cannot change the tablespace of the currently open database
+ALTER DATABASE "current_database" SET TABLESPACE pg_default;
+-- test alter database rename
+ALTER DATABASE current_database rename to db2;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: ALTER DATABASE current_database rename to db2;
+                       ^
+COMMENT ON DATABASE "current_database" IS 'changed from current_database';
+ALTER DATABASE "current_database" rename to db2;
+ALTER DATABASE db2 rename to current_database;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: ALTER DATABASE db2 rename to current_database;
+                                     ^
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1' or d.datname='db2'
+ORDER BY 1;
+ Name |          Description          
+------+-------------------------------
+ db1  | db1
+ db2  | changed from current_database
+(2 rows)
+
+-- test alter database set parameter
+ALTER DATABASE current_database SET parallel_tuple_cost=0.3;
+\c db1
+show parallel_tuple_cost;
+ parallel_tuple_cost 
+---------------------
+ 0.3
+(1 row)
+
+ALTER DATABASE current_database RESET parallel_tuple_cost;
+\c db1
+show parallel_tuple_cost;
+ parallel_tuple_cost 
+---------------------
+ 0.1
+(1 row)
+
+-- clean up
+\c postgres
+DROP DATABASE IF EXISTS "current_database";
+NOTICE:  database "current_database" does not exist, skipping
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db2;
+DROP ROLE dbuser1;
+DROP ROLE dbuser2;
+DROP ROLE dbuser3;
diff --git a/src/test/regress/expected/publication.out b/src/test/regress/expected/publication.out
index b101331..81d8629 100644
--- a/src/test/regress/expected/publication.out
+++ b/src/test/regress/expected/publication.out
@@ -206,6 +206,17 @@ ALTER PUBLICATION testpub2 ADD TABLE testpub_tbl1;  -- ok
 DROP PUBLICATION testpub2;
 SET ROLE regress_publication_user;
 REVOKE CREATE ON DATABASE regression FROM regress_publication_user2;
+--- test grant on database current_database
+GRANT CREATE ON DATABASE CURRENT_DATABASE TO regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- ok
+DROP PUBLICATION testpub2;
+SET ROLE regress_publication_user;
+REVOKE CREATE ON DATABASE CURRENT_DATABASE FROM regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- fail
+ERROR:  permission denied for database regression
+SET ROLE regress_publication_user;
 DROP TABLE testpub_parted;
 DROP VIEW testpub_view;
 DROP TABLE testpub_tbl1;
diff --git a/src/test/regress/expected/rolenames.out b/src/test/regress/expected/rolenames.out
index dce82f5..ab02155 100644
--- a/src/test/regress/expected/rolenames.out
+++ b/src/test/regress/expected/rolenames.out
@@ -369,6 +369,26 @@ SELECT * FROM chksetconfig();
 ----+------+------------+-----------
 (0 rows)
 
+--  ALTER ROLE IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE SET application_name to 'FOO';
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+     db     |       role       |  rolkeyword  |         setconfig         
+------------+------------------+--------------+---------------------------
+ regression | Public           | -            | {application_name=BARBAR}
+ regression | current_user     | -            | {application_name=FOOFOO}
+ regression | regress_testrol2 | current_user | {application_name=FOO}
+(3 rows)
+
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+ db | role | rolkeyword | setconfig 
+----+------+------------+-----------
+(0 rows)
+
 ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ'; -- error
 ERROR:  syntax error at or near "CURRENT_ROLE"
 LINE 1: ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ';
@@ -421,6 +441,26 @@ SELECT * FROM chksetconfig();
 ----+------+------------+-----------
 (0 rows)
 
+--  ALTER USER IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE SET application_name to 'BAR';
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+     db     |       role       |  rolkeyword  |         setconfig         
+------------+------------------+--------------+---------------------------
+ regression | Public           | -            | {application_name=BARBAR}
+ regression | current_user     | -            | {application_name=FOOFOO}
+ regression | regress_testrol1 | session_user | {application_name=BAR}
+(3 rows)
+
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+ db | role | rolkeyword | setconfig 
+----+------+------------+-----------
+(0 rows)
+
 ALTER USER CURRENT_USER SET application_name to 'BAZ'; -- error
 ALTER USER USER SET application_name to 'BOOM'; -- error
 ERROR:  syntax error at or near "USER"
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index e224977..ef69620 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -123,3 +123,4 @@ test: event_trigger
 
 # run stats by itself because its delay may be insufficient under heavy load
 test: stats
+test: dbname
\ No newline at end of file
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 9fc5f1a..5bcb13d 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -186,3 +186,4 @@ test: reloptions
 test: hash_part
 test: event_trigger
 test: stats
+test: dbname
diff --git a/src/test/regress/sql/dbname.sql b/src/test/regress/sql/dbname.sql
new file mode 100644
index 0000000..5c8b36e
--- /dev/null
+++ b/src/test/regress/sql/dbname.sql
@@ -0,0 +1,77 @@
+CREATE ROLE dbuser1 with LOGIN;
+CREATE ROLE dbuser2 with SUPERUSER LOGIN;
+CREATE ROLE dbuser3 with SUPERUSER LOGIN;
+
+DROP DATABASE IF EXISTS db1;
+CREATE DATABASE db1 with owner=dbuser1;
+CREATE DATABASE "current_database" with owner=dbuser1;
+CREATE DATABASE current_database with owner=dbuser1;
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+
+\c db1;
+SELECT CURRENT_DATABASE;
+
+
+COMMENT ON DATABASE current_database IS 'db1';
+COMMENT ON DATABASE "current_database" IS 'db2';
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+-- test alter owner
+ALTER DATABASE current_database OWNER to dbuser2; 
+ALTER DATABASE "current_database" OWNER to dbuser2;
+
+SELECT d.datname as "Name",
+       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+-- test alter database tablespace
+ALTER DATABASE current_database SET TABLESPACE pg_default;
+ALTER DATABASE "current_database" SET TABLESPACE pg_default;
+
+-- test alter database rename
+ALTER DATABASE current_database rename to db2;
+COMMENT ON DATABASE "current_database" IS 'changed from current_database';
+ALTER DATABASE "current_database" rename to db2;
+ALTER DATABASE db2 rename to current_database;
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1' or d.datname='db2'
+ORDER BY 1;
+
+-- test alter database set parameter
+ALTER DATABASE current_database SET parallel_tuple_cost=0.3;
+\c db1
+show parallel_tuple_cost;
+ALTER DATABASE current_database RESET parallel_tuple_cost;
+\c db1
+show parallel_tuple_cost;
+
+-- clean up
+\c postgres
+
+DROP DATABASE IF EXISTS "current_database";
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db2;
+DROP ROLE dbuser1;
+DROP ROLE dbuser2;
+DROP ROLE dbuser3;
diff --git a/src/test/regress/sql/publication.sql b/src/test/regress/sql/publication.sql
index 815410b..0ee3fd3 100644
--- a/src/test/regress/sql/publication.sql
+++ b/src/test/regress/sql/publication.sql
@@ -112,6 +112,18 @@ DROP PUBLICATION testpub2;
 SET ROLE regress_publication_user;
 REVOKE CREATE ON DATABASE regression FROM regress_publication_user2;
 
+--- test grant on database current_database
+GRANT CREATE ON DATABASE CURRENT_DATABASE TO regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- ok
+DROP PUBLICATION testpub2;
+
+SET ROLE regress_publication_user;
+REVOKE CREATE ON DATABASE CURRENT_DATABASE FROM regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- fail
+SET ROLE regress_publication_user;
+
 DROP TABLE testpub_parted;
 DROP VIEW testpub_view;
 DROP TABLE testpub_tbl1;
diff --git a/src/test/regress/sql/rolenames.sql b/src/test/regress/sql/rolenames.sql
index 4c5706b..ff11931 100644
--- a/src/test/regress/sql/rolenames.sql
+++ b/src/test/regress/sql/rolenames.sql
@@ -146,6 +146,15 @@ ALTER ROLE "Public" RESET application_name;
 ALTER ROLE ALL RESET application_name;
 SELECT * FROM chksetconfig();
 
+--  ALTER ROLE IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE SET application_name to 'FOO';
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
 
 ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ'; -- error
 ALTER ROLE USER SET application_name to 'BOOM'; -- error
@@ -170,6 +179,16 @@ ALTER USER ALL RESET application_name;
 SELECT * FROM chksetconfig();
 
 
+--  ALTER USER IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE SET application_name to 'BAR';
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+
 ALTER USER CURRENT_USER SET application_name to 'BAZ'; -- error
 ALTER USER USER SET application_name to 'BOOM'; -- error
 ALTER USER PUBLIC SET application_name to 'BOMB'; -- error

diff --git a/doc/src/sgml/ref/alter_database.sgml b/doc/src/sgml/ref/alter_database.sgml
index 7db878c..48cd840 100644
--- a/doc/src/sgml/ref/alter_database.sgml
+++ b/doc/src/sgml/ref/alter_database.sgml
@@ -31,14 +31,14 @@ ALTER DATABASE <replaceable class="parameter">name</replaceable> [ [ WITH ] <rep
 
 ALTER DATABASE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER DATABASE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
 
 ALTER DATABASE <replaceable class="parameter">name</replaceable> SET TABLESPACE <replaceable class="parameter">new_tablespace</replaceable>
 
-ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET <replaceable>configuration_parameter</replaceable>
-ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET ALL
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } RESET <replaceable>configuration_parameter</replaceable>
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } RESET ALL
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/alter_role.sgml b/doc/src/sgml/ref/alter_role.sgml
index 573a3e8..cf7b575 100644
--- a/doc/src/sgml/ref/alter_role.sgml
+++ b/doc/src/sgml/ref/alter_role.sgml
@@ -38,16 +38,21 @@ ALTER ROLE <replaceable class="parameter">role_specification</replaceable> [ WIT
 
 ALTER ROLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET ALL
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET ALL
 
 <phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
 
     <replaceable class="parameter">role_name</replaceable>
   | CURRENT_USER
   | SESSION_USER
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/alter_user.sgml b/doc/src/sgml/ref/alter_user.sgml
index 8f50f43..cbf8163 100644
--- a/doc/src/sgml/ref/alter_user.sgml
+++ b/doc/src/sgml/ref/alter_user.sgml
@@ -38,16 +38,21 @@ ALTER USER <replaceable class="parameter">role_specification</replaceable> [ WIT
 
 ALTER USER <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET ALL
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET ALL
 
 <phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
 
     <replaceable class="parameter">role_name</replaceable>
   | CURRENT_USER
   | SESSION_USER
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 965c5a4..025b672 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -31,7 +31,7 @@ COMMENT ON
   CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
   CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ON DOMAIN <replaceable class="parameter">domain_name</replaceable> |
   CONVERSION <replaceable class="parameter">object_name</replaceable> |
-  DATABASE <replaceable class="parameter">object_name</replaceable> |
+  DATABASE <replaceable class="parameter">database_specification</replaceable> |
   DOMAIN <replaceable class="parameter">object_name</replaceable> |
   EXTENSION <replaceable class="parameter">object_name</replaceable> |
   EVENT TRIGGER <replaceable class="parameter">object_name</replaceable> |
@@ -73,6 +73,11 @@ COMMENT ON
 * |
 [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] |
 [ [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] ] ORDER BY [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ]
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
@@ -315,6 +320,7 @@ COMMENT ON CONVERSION my_conv IS 'Conversion to UTF8';
 COMMENT ON CONSTRAINT bar_col_cons ON bar IS 'Constrains column col';
 COMMENT ON CONSTRAINT dom_col_constr ON DOMAIN dom IS 'Constrains col of domain';
 COMMENT ON DATABASE my_database IS 'Development Database';
+COMMENT ON DATABASE current_database IS 'Comment on current Database';
 COMMENT ON DOMAIN my_domain IS 'Email Address Domain';
 COMMENT ON EXTENSION hstore IS 'implements the hstore data type';
 COMMENT ON FOREIGN DATA WRAPPER mywrapper IS 'my foreign data wrapper';
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index ff64c7a..880a30d 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -39,9 +39,14 @@ GRANT { { USAGE | SELECT | UPDATE }
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
 
 GRANT { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
-    ON DATABASE <replaceable>database_name</replaceable> [, ...]
+    ON DATABASE <replaceable>database_specification</replaceable> [, ...]
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
 
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
+
 GRANT { USAGE | ALL [ PRIVILEGES ] }
     ON DOMAIN <replaceable>domain_name</replaceable> [, ...]
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 7018202..f7a3055 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -46,10 +46,15 @@ REVOKE [ GRANT OPTION FOR ]
 
 REVOKE [ GRANT OPTION FOR ]
     { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
-    ON DATABASE <replaceable>database_name</replaceable> [, ...]
+    ON DATABASE <replaceable>database_specification</replaceable> [, ...]
     FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
     [ CASCADE | RESTRICT ]
 
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
+
 REVOKE [ GRANT OPTION FOR ]
     { USAGE | ALL [ PRIVILEGES ] }
     ON DOMAIN <replaceable>domain_name</replaceable> [, ...]
diff --git a/doc/src/sgml/ref/security_label.sgml b/doc/src/sgml/ref/security_label.sgml
index e9cfdec..c582c96 100644
--- a/doc/src/sgml/ref/security_label.sgml
+++ b/doc/src/sgml/ref/security_label.sgml
@@ -26,7 +26,7 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
   TABLE <replaceable class="parameter">object_name</replaceable> |
   COLUMN <replaceable class="parameter">table_name</replaceable>.<replaceable class="parameter">column_name</replaceable> |
   AGGREGATE <replaceable class="parameter">aggregate_name</replaceable> ( <replaceable>aggregate_signature</replaceable> ) |
-  DATABASE <replaceable class="parameter">object_name</replaceable> |
+  DATABASE <replaceable class="parameter">database_specification</replaceable> |
   DOMAIN <replaceable class="parameter">object_name</replaceable> |
   EVENT TRIGGER <replaceable class="parameter">object_name</replaceable> |
   FOREIGN TABLE <replaceable class="parameter">object_name</replaceable>
@@ -51,6 +51,11 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
 * |
 [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] |
 [ [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] ] ORDER BY [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ]
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index fac8061..68d7c63 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -65,6 +65,7 @@
 #include "foreign/foreign.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
+#include "nodes/parsenodes.h"
 #include "parser/parse_func.h"
 #include "parser/parse_type.h"
 #include "utils/acl.h"
@@ -657,10 +658,10 @@ objectNamesToOids(GrantObjectType objtype, List *objnames)
 		case ACL_OBJECT_DATABASE:
 			foreach(cell, objnames)
 			{
-				char	   *dbname = strVal(lfirst(cell));
+				DbSpec	   *dbspec = lfirst(cell);
 				Oid			dbid;
 
-				dbid = get_database_oid(dbname, false);
+				dbid = get_dbspec_oid(dbspec,false);
 				objects = lappend_oid(objects, dbid);
 			}
 			break;
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index bc999ca..a070930 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -868,6 +868,10 @@ get_object_address(ObjectType objtype, Node *object,
 				}
 				break;
 			case OBJECT_DATABASE:
+				address.classId = DatabaseRelationId;
+				address.objectId = get_dbspec_oid((DbSpec *)object, missing_ok);
+				address.objectSubId = 0;
+				break;
 			case OBJECT_EXTENSION:
 			case OBJECT_TABLESPACE:
 			case OBJECT_ROLE:
@@ -2247,7 +2251,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
 		case OBJECT_DATABASE:
 			if (!pg_database_ownercheck(address.objectId, roleid))
 				aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-							   strVal((Value *) object));
+							   get_dbspec_name((DbSpec *)object));
 			break;
 		case OBJECT_TYPE:
 		case OBJECT_DOMAIN:
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 3995c5e..5f9dd9f 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -806,7 +806,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
 	switch (stmt->objectType)
 	{
 		case OBJECT_DATABASE:
-			return AlterDatabaseOwner(strVal((Value *) stmt->object), newowner);
+			return AlterDatabaseOwner((DbSpec *) stmt->object, newowner);
 
 		case OBJECT_SCHEMA:
 			return AlterSchemaOwner(strVal((Value *) stmt->object), newowner);
diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c
index 2f2e69b..64bd07d 100644
--- a/src/backend/commands/comment.c
+++ b/src/backend/commands/comment.c
@@ -52,13 +52,15 @@ CommentObject(CommentStmt *stmt)
 	 */
 	if (stmt->objtype == OBJECT_DATABASE)
 	{
-		char	   *database = strVal((Value *) stmt->object);
-
-		if (!OidIsValid(get_database_oid(database, true)))
+		if (!OidIsValid(get_dbspec_oid((DbSpec *)stmt->object, true)))
 		{
+			char		*dbname = NULL;
+
+			dbname = get_dbspec_name((DbSpec *)stmt->object);
+
 			ereport(WARNING,
 					(errcode(ERRCODE_UNDEFINED_DATABASE),
-					 errmsg("database \"%s\" does not exist", database)));
+					 errmsg("database \"%s\" does not exist", dbname)));
 			return address;
 		}
 	}
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 0b111fc..490f420 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -1413,6 +1413,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	Datum		new_record[Natts_pg_database];
 	bool		new_record_nulls[Natts_pg_database];
 	bool		new_record_repl[Natts_pg_database];
+	char		*dbname = NULL;
+
+	dbname = get_dbspec_name(stmt->dbspec);
 
 	/* Extract options from the statement node tree */
 	foreach(option, stmt->options)
@@ -1477,7 +1480,7 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 					 parser_errposition(pstate, dtablespace->location)));
 		/* this case isn't allowed within a transaction block */
 		PreventTransactionChain(isTopLevel, "ALTER DATABASE SET TABLESPACE");
-		movedb(stmt->dbname, defGetString(dtablespace));
+		movedb(dbname, defGetString(dtablespace));
 		return InvalidOid;
 	}
 
@@ -1503,20 +1506,20 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	ScanKeyInit(&scankey,
 				Anum_pg_database_datname,
 				BTEqualStrategyNumber, F_NAMEEQ,
-				CStringGetDatum(stmt->dbname));
+				CStringGetDatum(dbname));
 	scan = systable_beginscan(rel, DatabaseNameIndexId, true,
 							  NULL, 1, &scankey);
 	tuple = systable_getnext(scan);
 	if (!HeapTupleIsValid(tuple))
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_DATABASE),
-				 errmsg("database \"%s\" does not exist", stmt->dbname)));
+				 errmsg("database \"%s\" does not exist", dbname)));
 
 	dboid = HeapTupleGetOid(tuple);
 
 	if (!pg_database_ownercheck(HeapTupleGetOid(tuple), GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-					   stmt->dbname);
+					   dbname);
 
 	/*
 	 * In order to avoid getting locked out and having to go through
@@ -1574,7 +1577,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 Oid
 AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 {
-	Oid			datid = get_database_oid(stmt->dbname, false);
+	Oid			datid;
+
+	datid = get_dbspec_oid(stmt->dbspec, false);
 
 	/*
 	 * Obtain a lock on the database and make sure it didn't go away in the
@@ -1584,7 +1589,7 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 
 	if (!pg_database_ownercheck(datid, GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-					   stmt->dbname);
+				get_dbspec_name(stmt->dbspec));
 
 	AlterSetting(datid, InvalidOid, stmt->setstmt);
 
@@ -1598,7 +1603,7 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
  * ALTER DATABASE name OWNER TO newowner
  */
 ObjectAddress
-AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
+AlterDatabaseOwner(const DbSpec *dbspec, Oid newOwnerId)
 {
 	Oid			db_id;
 	HeapTuple	tuple;
@@ -1607,6 +1612,9 @@ AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
 	SysScanDesc scan;
 	Form_pg_database datForm;
 	ObjectAddress address;
+	char		*dbname;
+
+	dbname = get_dbspec_name(dbspec);
 
 	/*
 	 * Get the old tuple.  We don't need a lock on the database per se,
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index d559c29..9e82d19 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -927,9 +927,9 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 	}
 
 	/* look up and lock the database, if specified */
-	if (stmt->database != NULL)
+	if (stmt->dbspec != NULL)
 	{
-		databaseid = get_database_oid(stmt->database, false);
+		databaseid = get_dbspec_oid(stmt->dbspec,false);
 		shdepLockAndCheckObject(DatabaseRelationId, databaseid);
 
 		if (!stmt->role)
@@ -940,11 +940,11 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 			 */
 			if (!pg_database_ownercheck(databaseid, GetUserId()))
 				aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
-							   stmt->database);
+						get_dbspec_name(stmt->dbspec));
 		}
 	}
 
-	if (!stmt->role && !stmt->database)
+	if (!stmt->role && !stmt->dbspec)
 	{
 		/* Must be superuser to alter settings globally. */
 		if (!superuser())
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index f646fd9..2558177 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -2320,6 +2320,7 @@ ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op)
 			*op->resnull = fcinfo.isnull;
 			break;
 		case SVFOP_CURRENT_CATALOG:
+		case SVFOP_CURRENT_DATABASE:
 			InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
 			*op->resvalue = current_database(&fcinfo);
 			*op->resnull = fcinfo.isnull;
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index ddbbc79..3c3c8be 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2924,6 +2924,18 @@ _copyTriggerTransition(const TriggerTransition *from)
 	return newnode;
 }
 
+static DbSpec *
+_copyDatabaseSpec(const DbSpec *from)
+{
+	DbSpec   *newnode = makeNode(DbSpec);
+
+	COPY_SCALAR_FIELD(dbtype);
+	COPY_STRING_FIELD(dbname);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
 static Query *
 _copyQuery(const Query *from)
 {
@@ -3748,7 +3760,7 @@ _copyAlterDatabaseStmt(const AlterDatabaseStmt *from)
 {
 	AlterDatabaseStmt *newnode = makeNode(AlterDatabaseStmt);
 
-	COPY_STRING_FIELD(dbname);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(options);
 
 	return newnode;
@@ -3759,7 +3771,7 @@ _copyAlterDatabaseSetStmt(const AlterDatabaseSetStmt *from)
 {
 	AlterDatabaseSetStmt *newnode = makeNode(AlterDatabaseSetStmt);
 
-	COPY_STRING_FIELD(dbname);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(setstmt);
 
 	return newnode;
@@ -4238,7 +4250,7 @@ _copyAlterRoleSetStmt(const AlterRoleSetStmt *from)
 	AlterRoleSetStmt *newnode = makeNode(AlterRoleSetStmt);
 
 	COPY_NODE_FIELD(role);
-	COPY_STRING_FIELD(database);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(setstmt);
 
 	return newnode;
@@ -5565,7 +5577,9 @@ copyObjectImpl(const void *from)
 		case T_PartitionCmd:
 			retval = _copyPartitionCmd(from);
 			break;
-
+		case T_DbSpec:
+			retval = _copyDatabaseSpec(from);
+			break;
 			/*
 			 * MISCELLANEOUS NODES
 			 */
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 30ccc9c..d939139 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1645,7 +1645,7 @@ _equalCreatedbStmt(const CreatedbStmt *a, const CreatedbStmt *b)
 static bool
 _equalAlterDatabaseStmt(const AlterDatabaseStmt *a, const AlterDatabaseStmt *b)
 {
-	COMPARE_STRING_FIELD(dbname);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(options);
 
 	return true;
@@ -1654,7 +1654,7 @@ _equalAlterDatabaseStmt(const AlterDatabaseStmt *a, const AlterDatabaseStmt *b)
 static bool
 _equalAlterDatabaseSetStmt(const AlterDatabaseSetStmt *a, const AlterDatabaseSetStmt *b)
 {
-	COMPARE_STRING_FIELD(dbname);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(setstmt);
 
 	return true;
@@ -2061,7 +2061,7 @@ static bool
 _equalAlterRoleSetStmt(const AlterRoleSetStmt *a, const AlterRoleSetStmt *b)
 {
 	COMPARE_NODE_FIELD(role);
-	COMPARE_STRING_FIELD(database);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(setstmt);
 
 	return true;
@@ -2887,6 +2887,16 @@ _equalPartitionCmd(const PartitionCmd *a, const PartitionCmd *b)
 	return true;
 }
 
+static bool
+_equalDatabaseSpec(const DbSpec *a, const DbSpec *b)
+{
+	COMPARE_SCALAR_FIELD(dbtype);
+	COMPARE_STRING_FIELD(dbname);
+	COMPARE_LOCATION_FIELD(location);
+
+	return true;
+}
+
 /*
  * Stuff from pg_list.h
  */
@@ -3703,6 +3713,9 @@ equal(const void *a, const void *b)
 		case T_PartitionCmd:
 			retval = _equalPartitionCmd(a, b);
 			break;
+		case T_DbSpec:
+			retval = _equalDatabaseSpec(a, b);
+			break;
 
 		default:
 			elog(ERROR, "unrecognized node type: %d",
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index e42b7ca..0bc0c94 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -187,7 +187,7 @@ static void processCASbits(int cas_bits, int location, const char *constrType,
 			   bool *deferrable, bool *initdeferred, bool *not_valid,
 			   bool *no_inherit, core_yyscan_t yyscanner);
 static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
-
+static DbSpec *makeDbSpec(DbSpecType type, int location);
 %}
 
 %pure-parser
@@ -241,6 +241,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	PartitionSpec		*partspec;
 	PartitionBoundSpec	*partboundspec;
 	RoleSpec			*rolespec;
+	DbSpec				*dbspec;
 }
 
 %type <node>	stmt schema_stmt
@@ -316,7 +317,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 %type <str>		opt_type
 %type <str>		foreign_server_version opt_foreign_server_version
-%type <str>		opt_in_database
+%type <dbspec>		opt_in_database
 
 %type <str>		OptSchemaName
 %type <list>	OptSchemaEltList
@@ -397,7 +398,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				transform_element_list transform_type_list
 				TriggerTransitions TriggerReferencing
 				publication_name_list
-				vacuum_relation_list opt_vacuum_relation_list
+				vacuum_relation_list opt_vacuum_relation_list db_spec_name_list
 
 %type <list>	group_by_list
 %type <node>	group_by_item empty_grouping_set rollup_clause cube_clause
@@ -572,6 +573,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				opt_frame_clause frame_extent frame_bound
 %type <str>		opt_existing_window_name
 %type <boolean> opt_if_not_exists
+%type <dbspec>	db_spec_name
 %type <ival>	generated_when override_kind
 %type <partspec>	PartitionSpec OptPartitionSpec
 %type <str>			part_strategy
@@ -617,7 +619,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	COMMITTED CONCURRENTLY CONFIGURATION CONFLICT CONNECTION CONSTRAINT
 	CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE
 	CROSS CSV CUBE CURRENT_P
-	CURRENT_CATALOG CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
+	CURRENT_CATALOG CURRENT_DATABASE CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
 
 	DATA_P DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
@@ -1156,7 +1158,7 @@ AlterRoleStmt:
 
 opt_in_database:
 			   /* EMPTY */					{ $$ = NULL; }
-			| IN_P DATABASE database_name	{ $$ = $3; }
+			| IN_P DATABASE db_spec_name	{ $$ = $3; }
 		;
 
 AlterRoleSetStmt:
@@ -1164,7 +1166,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->database = $4;
+					n->dbspec = $4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1172,7 +1174,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = NULL;
-					n->database = $4;
+					n->dbspec = $4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1180,7 +1182,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->database = $4;
+					n->dbspec = $4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1188,7 +1190,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = NULL;
-					n->database = $4;
+					n->dbspec = $4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -6400,6 +6402,14 @@ CommentStmt:
 					n->comment = $6;
 					$$ = (Node *) n;
 				}
+			| COMMENT ON DATABASE db_spec_name IS comment_text
+				{
+					CommentStmt *n = makeNode(CommentStmt);
+					n->objtype = OBJECT_DATABASE;
+					n->object = (Node *) $4;
+					n->comment = $6;
+					$$ = (Node *) n;
+				}
 			| COMMENT ON TYPE_P Typename IS comment_text
 				{
 					CommentStmt *n = makeNode(CommentStmt);
@@ -6564,7 +6574,6 @@ comment_type_any_name:
 /* object types taking name */
 comment_type_name:
 			ACCESS METHOD						{ $$ = OBJECT_ACCESS_METHOD; }
-			| DATABASE							{ $$ = OBJECT_DATABASE; }
 			| EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
 			| EXTENSION							{ $$ = OBJECT_EXTENSION; }
 			| FOREIGN DATA_P WRAPPER			{ $$ = OBJECT_FDW; }
@@ -6613,6 +6622,16 @@ SecLabelStmt:
 					n->label = $8;
 					$$ = (Node *) n;
 				}
+			| SECURITY LABEL opt_provider ON DATABASE db_spec_name
+			IS security_label
+				{
+					SecLabelStmt *n = makeNode(SecLabelStmt);
+					n->provider = $3;
+					n->objtype = OBJECT_DATABASE;
+					n->object = (Node *) $6;
+					n->label = $8;
+					$$ = (Node *) n;
+				}
 			| SECURITY LABEL opt_provider ON TYPE_P Typename
 			  IS security_label
 				{
@@ -6701,8 +6720,7 @@ security_label_type_any_name:
 
 /* object types taking name */
 security_label_type_name:
-			DATABASE							{ $$ = OBJECT_DATABASE; }
-			| EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
+			EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
 			| opt_procedural LANGUAGE			{ $$ = OBJECT_LANGUAGE; }
 			| PUBLICATION						{ $$ = OBJECT_PUBLICATION; }
 			| ROLE								{ $$ = OBJECT_ROLE; }
@@ -7062,7 +7080,7 @@ privilege_target:
 					n->objs = $2;
 					$$ = n;
 				}
-			| DATABASE name_list
+			| DATABASE db_spec_name_list
 				{
 					PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
 					n->targtype = ACL_TARGET_OBJECT;
@@ -9287,11 +9305,11 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
 					n->newowner = $6;
 					$$ = (Node *)n;
 				}
-			| ALTER DATABASE database_name OWNER TO RoleSpec
+			| ALTER DATABASE db_spec_name OWNER TO RoleSpec
 				{
 					AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
 					n->objectType = OBJECT_DATABASE;
-					n->object = (Node *) makeString($3);
+					n->object = (Node *) $3;
 					n->newowner = $6;
 					$$ = (Node *)n;
 				}
@@ -10113,24 +10131,24 @@ opt_equal:	'='										{}
  *****************************************************************************/
 
 AlterDatabaseStmt:
-			ALTER DATABASE database_name WITH createdb_opt_list
+			ALTER DATABASE db_spec_name WITH createdb_opt_list
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = $5;
 					$$ = (Node *)n;
 				 }
-			| ALTER DATABASE database_name createdb_opt_list
+			| ALTER DATABASE db_spec_name createdb_opt_list
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = $4;
 					$$ = (Node *)n;
 				 }
-			| ALTER DATABASE database_name SET TABLESPACE name
+			| ALTER DATABASE db_spec_name SET TABLESPACE name
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = list_make1(makeDefElem("tablespace",
 														(Node *)makeString($6), @6));
 					$$ = (Node *)n;
@@ -10138,10 +10156,10 @@ AlterDatabaseStmt:
 		;
 
 AlterDatabaseSetStmt:
-			ALTER DATABASE database_name SetResetClause
+			ALTER DATABASE db_spec_name SetResetClause
 				{
 					AlterDatabaseSetStmt *n = makeNode(AlterDatabaseSetStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->setstmt = $4;
 					$$ = (Node *)n;
 				}
@@ -13665,6 +13683,10 @@ func_expr_common_subexpr:
 				{
 					$$ = makeSQLValueFunction(SVFOP_SESSION_USER, -1, @1);
 				}
+			| CURRENT_DATABASE
+				{
+					$$ = makeSQLValueFunction(SVFOP_CURRENT_DATABASE, -1, @1);
+				}
 			| USER
 				{
 					$$ = makeSQLValueFunction(SVFOP_USER, -1, @1);
@@ -14635,7 +14657,36 @@ name_list:	name
 name:		ColId									{ $$ = $1; };
 
 database_name:
-			ColId									{ $$ = $1; };
+			ColId									{ $$ = $1; }
+			| CURRENT_DATABASE
+				{
+					ereport(ERROR,
+							(errcode(ERRCODE_RESERVED_NAME),
+							 errmsg("%s cannot be used as a database name here",
+									"CURRENT_DATABASE"),
+							 parser_errposition(@1)));
+				}
+		;
+
+db_spec_name_list:	db_spec_name
+					{ $$ = list_make1($1); }
+			| db_spec_name_list ',' db_spec_name
+					{ $$ = lappend($1, $3); }
+		;
+
+
+db_spec_name:
+			ColId
+				{
+					DbSpec *n = makeDbSpec(DBSPEC_CSTRING, @1);
+					n->dbname = pstrdup($1);
+					$$ = n;
+				}
+			| CURRENT_DATABASE
+				{
+					$$ = makeDbSpec(DBSPEC_CURRENT_DATABASE, @1);
+				}
+		;
 
 access_method:
 			ColId									{ $$ = $1; };
@@ -14661,6 +14712,8 @@ func_name:	type_function_name
 						$$ = check_func_name(lcons(makeString($1), $2),
 											 yyscanner);
 					}
+			| CURRENT_DATABASE
+					{ $$ = list_make1(makeString("current_database")); }
 		;
 
 
@@ -15316,6 +15369,7 @@ reserved_keyword:
 			| CONSTRAINT
 			| CREATE
 			| CURRENT_CATALOG
+			| CURRENT_DATABASE
 			| CURRENT_DATE
 			| CURRENT_ROLE
 			| CURRENT_TIME
@@ -16227,6 +16281,20 @@ makeRecursiveViewSelect(char *relname, List *aliases, Node *query)
 	return (Node *) s;
 }
 
+/* makeDbSpec
+ * Create a DbSpec with the given type
+ */
+static DbSpec *
+makeDbSpec(DbSpecType type, int location)
+{
+	DbSpec *spec = makeNode(DbSpec);
+
+	spec->dbtype = type;
+	spec->location = location;
+
+	return spec;
+}
+
 /* parser_init()
  * Initialize to parse one query string
  */
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index b2f5e46..74a0ada 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -2334,6 +2334,7 @@ transformSQLValueFunction(ParseState *pstate, SQLValueFunction *svf)
 		case SVFOP_SESSION_USER:
 		case SVFOP_CURRENT_CATALOG:
 		case SVFOP_CURRENT_SCHEMA:
+		case SVFOP_CURRENT_DATABASE:
 			svf->type = NAMEOID;
 			break;
 	}
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index ea209cd..14cee21 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1882,6 +1882,9 @@ FigureColnameInternal(Node *node, char **name)
 				case SVFOP_CURRENT_SCHEMA:
 					*name = "current_schema";
 					return 2;
+				case SVFOP_CURRENT_DATABASE:
+					*name = "current_database";
+					return 2;
 			}
 			break;
 		case T_XmlExpr:
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index c11f3dd..75829ec 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -24,6 +24,7 @@
 #include "catalog/pg_auth_members.h"
 #include "catalog/pg_type.h"
 #include "catalog/pg_class.h"
+#include "catalog/pg_database.h"
 #include "commands/dbcommands.h"
 #include "commands/proclang.h"
 #include "commands/tablespace.h"
@@ -5273,3 +5274,64 @@ check_rolespec_name(const RoleSpec *role, const char *detail_msg)
 							role->rolename)));
 	}
 }
+
+/*
+ * Given a DbSpec, returns a palloc'ed copy of the corresponding database name.
+ */
+char *
+get_dbspec_name(const DbSpec *db)
+{
+	char	   *dbname;
+	HeapTuple	tuple;
+	Form_pg_database dbForm;
+
+	switch (db->dbtype)
+	{
+		case DBSPEC_CSTRING:
+			Assert(db->dbname);
+			dbname = db->dbname;
+			break;
+
+		case DBSPEC_CURRENT_DATABASE:
+			tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
+			if (!HeapTupleIsValid(tuple))
+				elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
+
+			dbForm = (Form_pg_database) GETSTRUCT(tuple);
+			dbname = pstrdup(NameStr(dbForm->datname));
+			ReleaseSysCache(tuple);
+			break;
+
+		default:
+			elog(ERROR, "unexpected database type %d", db->dbtype);
+	}
+
+	return dbname;
+}
+
+/*
+ * Given a DbSpec node, return the OID it corresponds to.  If missing_ok is
+ * true, return InvalidOid if the database does not exist.
+ */
+Oid
+get_dbspec_oid(const DbSpec *db, bool missing_ok)
+{
+	Oid			oid;
+
+	switch (db->dbtype)
+	{
+		case DBSPEC_CSTRING:
+			Assert(db->dbname);
+			oid = get_database_oid(db->dbname, missing_ok);
+			break;
+
+		case DBSPEC_CURRENT_DATABASE:
+			oid = MyDatabaseId;
+			break;
+
+		default:
+			elog(ERROR, "unexpected database type %d", db->dbtype);
+	}
+
+	return oid;
+}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 9cdbb06..6952588 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8357,6 +8357,10 @@ get_rule_expr(Node *node, deparse_context *context,
 					case SVFOP_CURRENT_SCHEMA:
 						appendStringInfoString(buf, "CURRENT_SCHEMA");
 						break;
+					case SVFOP_CURRENT_DATABASE:
+						appendStringInfoString(buf, "CURRENT_DATABASE");
+						break;
+
 				}
 			}
 			break;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 32ad600..db581c0 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -682,6 +682,40 @@ emitShSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
 }
 
 /*
+ * emitDatabaseSecLabels
+ *
+ * Format security label data on database.
+ */
+void
+emitDatabaseSecLabels(PGconn *conn, PGresult *res, PQExpBuffer buffer,
+				const char *objname, bool current_datbase)
+{
+	int			i;
+
+	for (i = 0; i < PQntuples(res); i++)
+	{
+		char	   *provider = PQgetvalue(res, i, 0);
+		char	   *label = PQgetvalue(res, i, 1);
+
+		/* must use fmtId result before calling it again */
+		appendPQExpBuffer(buffer,
+						  "SECURITY LABEL FOR %s ON DATABASE",
+						  fmtId(provider));
+
+		if(current_datbase)
+			appendPQExpBuffer(buffer," CURRENT_DATABASE IS ");
+		else
+		{
+			appendPQExpBuffer(buffer,
+							  " %s IS ",
+							  fmtId(objname));
+		}
+		appendStringLiteralConn(buffer, label, conn);
+		appendPQExpBufferStr(buffer, ";\n");
+	}
+}
+
+/*
  * buildACLQueries
  *
  * Build the subqueries to extract out the correct set of ACLs to be
diff --git a/src/bin/pg_dump/dumputils.h b/src/bin/pg_dump/dumputils.h
index d5f150d..766b46f 100644
--- a/src/bin/pg_dump/dumputils.h
+++ b/src/bin/pg_dump/dumputils.h
@@ -49,8 +49,10 @@ extern bool buildDefaultACLCommands(const char *type, const char *nspname,
 extern void buildShSecLabelQuery(PGconn *conn, const char *catalog_name,
 					 uint32 objectId, PQExpBuffer sql);
 extern void emitShSecLabels(PGconn *conn, PGresult *res,
-				PQExpBuffer buffer, const char *target, const char *objname);
-
+				PQExpBuffer buffer, const char *target,
+				const char *objname);
+extern void emitDatabaseSecLabels(PGconn *conn, PGresult *res,
+				PQExpBuffer buffer, const char *objname, bool current_datbase);
 extern void buildACLQueries(PQExpBuffer acl_subquery, PQExpBuffer racl_subquery,
 				PQExpBuffer init_acl_subquery, PQExpBuffer init_racl_subquery,
 				const char *acl_column, const char *acl_owner,
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 27628a3..3bfbda2 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -2803,7 +2803,10 @@ dumpDatabase(Archive *fout)
 			 * Generates warning when loaded into a differently-named
 			 * database.
 			 */
-			appendPQExpBuffer(dbQry, "COMMENT ON DATABASE %s IS ", fmtId(datname));
+			if (fout->remoteVersion >= 110000)
+				appendPQExpBuffer(dbQry, "COMMENT ON DATABASE CURRENT_DATABASE IS ");
+			else
+				appendPQExpBuffer(dbQry, "COMMENT ON DATABASE %s IS ", fmtId(datname));
 			appendStringLiteralAH(dbQry, comment, fout);
 			appendPQExpBufferStr(dbQry, ";\n");
 
@@ -2832,7 +2835,10 @@ dumpDatabase(Archive *fout)
 		buildShSecLabelQuery(conn, "pg_database", dbCatId.oid, seclabelQry);
 		shres = ExecuteSqlQuery(fout, seclabelQry->data, PGRES_TUPLES_OK);
 		resetPQExpBuffer(seclabelQry);
-		emitShSecLabels(conn, shres, seclabelQry, "DATABASE", datname);
+		if (fout->remoteVersion >= 110000)
+			emitDatabaseSecLabels(conn, shres, seclabelQry, datname, true);
+		else
+			emitDatabaseSecLabels(conn, shres, seclabelQry, datname, false);
 		if (strlen(seclabelQry->data))
 			ArchiveEntry(fout, dbCatId, createDumpId(), datname, NULL, NULL,
 						 dba, false, "SECURITY LABEL", SECTION_NONE,
@@ -14788,9 +14794,17 @@ dumpSecLabel(Archive *fout, const char *target,
 		if (labels[i].objsubid != subid)
 			continue;
 
-		appendPQExpBuffer(query,
-						  "SECURITY LABEL FOR %s ON %s IS ",
-						  fmtId(labels[i].provider), target);
+		if (fout->remoteVersion >= 110000 && (strncmp(target, "DATABASE", 8) != 0))
+		{
+			appendPQExpBuffer(query,
+							  "SECURITY LABEL FOR %s ON DATABASE CURRENT_DATABASE IS ",
+							  fmtId(labels[i].provider));
+		}
+		else
+			appendPQExpBuffer(query,
+							  "SECURITY LABEL FOR %s ON %s IS ",
+							  fmtId(labels[i].provider), target);
+
 		appendStringLiteralAH(query, labels[i].label, fout);
 		appendPQExpBufferStr(query, ";\n");
 	}
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 7cf9bda..8ba5db2 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -1512,10 +1512,10 @@ qr/^ALTER (?!EVENT TRIGGER|LARGE OBJECT|PUBLICATION|SUBSCRIPTION)(.*) OWNER TO .
 			section_pre_data         => 1,
 			section_post_data        => 1, }, },
 
-	'COMMENT ON DATABASE postgres' => {
+	'COMMENT ON DATABASE CURRENT_DATABASE' => {
 		all_runs  => 1,
 		catch_all => 'COMMENT commands',
-		regexp    => qr/^COMMENT ON DATABASE postgres IS .*;/m,
+		regexp    => qr/^COMMENT ON DATABASE CURRENT_DATABASE IS .*;/m,
 		like      => {
 			binary_upgrade           => 1,
 			clean                    => 1,
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index 677c7fc..a08e99d 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -24,7 +24,7 @@ extern void dropdb(const char *dbname, bool missing_ok);
 extern ObjectAddress RenameDatabase(const char *oldname, const char *newname);
 extern Oid	AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel);
 extern Oid	AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
-extern ObjectAddress AlterDatabaseOwner(const char *dbname, Oid newOwnerId);
+extern ObjectAddress AlterDatabaseOwner(const DbSpec *dbspec, Oid newOwnerId);
 
 extern Oid	get_database_oid(const char *dbname, bool missingok);
 extern char *get_database_name(Oid dbid);
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 2eb3d6d..fd8115e 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -464,6 +464,7 @@ typedef enum NodeTag
 	T_OnConflictClause,
 	T_CommonTableExpr,
 	T_RoleSpec,
+	T_DbSpec,
 	T_TriggerTransition,
 	T_PartitionElem,
 	T_PartitionSpec,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b72178e..fd8f880 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -330,6 +330,23 @@ typedef struct RoleSpec
 } RoleSpec;
 
 /*
+ * DbSpecType - The type of a database name.
+ */
+typedef enum DbSpecType
+{
+	DBSPEC_CSTRING,				/* database name is stored as a C string */
+	DBSPEC_CURRENT_DATABASE		/* database name is CURRENT_DATABASE */
+} DbSpecType;
+
+typedef struct DbSpec
+{
+	NodeTag			type;
+	DbSpecType		dbtype;			/* Type of the database */
+	char			*dbname;		/* filled only for DBSPEC_CSTRING */
+	int				location;		/* token location, or -1 if unknown */
+} DbSpec;
+
+/*
  * FuncCall - a function or aggregate invocation
  *
  * agg_order (if not NIL) indicates we saw 'foo(... ORDER BY ...)', or if
@@ -2459,7 +2476,7 @@ typedef struct AlterRoleSetStmt
 {
 	NodeTag		type;
 	RoleSpec   *role;			/* role */
-	char	   *database;		/* database name, or NULL */
+	DbSpec	   *dbspec;			/* name of database to set */
 	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterRoleSetStmt;
 
@@ -3057,14 +3074,14 @@ typedef struct CreatedbStmt
 typedef struct AlterDatabaseStmt
 {
 	NodeTag		type;
-	char	   *dbname;			/* name of database to alter */
-	List	   *options;		/* List of DefElem nodes */
+	DbSpec		*dbspec;		/* name of database to alter */
+	List	   	*options;		/* List of DefElem nodes */
 } AlterDatabaseStmt;
 
 typedef struct AlterDatabaseSetStmt
 {
 	NodeTag		type;
-	char	   *dbname;			/* database name */
+	DbSpec		*dbspec;			/* DbSpec */
 	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterDatabaseSetStmt;
 
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1b4b0d7..efc1a9c 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1102,7 +1102,8 @@ typedef enum SQLValueFunctionOp
 	SVFOP_USER,
 	SVFOP_SESSION_USER,
 	SVFOP_CURRENT_CATALOG,
-	SVFOP_CURRENT_SCHEMA
+	SVFOP_CURRENT_SCHEMA,
+	SVFOP_CURRENT_DATABASE
 } SQLValueFunctionOp;
 
 typedef struct SQLValueFunction
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 26af944..fb706d0 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -105,6 +105,7 @@ PG_KEYWORD("csv", CSV, UNRESERVED_KEYWORD)
 PG_KEYWORD("cube", CUBE, UNRESERVED_KEYWORD)
 PG_KEYWORD("current", CURRENT_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("current_catalog", CURRENT_CATALOG, RESERVED_KEYWORD)
+PG_KEYWORD("current_database", CURRENT_DATABASE, RESERVED_KEYWORD)
 PG_KEYWORD("current_date", CURRENT_DATE, RESERVED_KEYWORD)
 PG_KEYWORD("current_role", CURRENT_ROLE, RESERVED_KEYWORD)
 PG_KEYWORD("current_schema", CURRENT_SCHEMA, TYPE_FUNC_NAME_KEYWORD)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 67c7b2d..44b9ab2 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -246,6 +246,8 @@ extern Oid	get_rolespec_oid(const RoleSpec *role, bool missing_ok);
 extern void check_rolespec_name(const RoleSpec *role, const char *detail_msg);
 extern HeapTuple get_rolespec_tuple(const RoleSpec *role);
 extern char *get_rolespec_name(const RoleSpec *role);
+extern char *get_dbspec_name(const DbSpec *db);
+extern Oid  get_dbspec_oid(const DbSpec *db, bool missing_ok);
 
 extern void select_best_grantor(Oid roleId, AclMode privileges,
 					const Acl *acl, Oid ownerId,
diff --git a/src/test/regress/expected/dbname.out b/src/test/regress/expected/dbname.out
new file mode 100644
index 0000000..cac34de
--- /dev/null
+++ b/src/test/regress/expected/dbname.out
@@ -0,0 +1,113 @@
+CREATE ROLE dbuser1 with LOGIN;
+CREATE ROLE dbuser2 with SUPERUSER LOGIN;
+CREATE ROLE dbuser3 with SUPERUSER LOGIN;
+DROP DATABASE IF EXISTS db1;
+NOTICE:  database "db1" does not exist, skipping
+CREATE DATABASE db1 with owner=dbuser1;
+CREATE DATABASE "current_database" with owner=dbuser1;
+CREATE DATABASE current_database with owner=dbuser1;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: CREATE DATABASE current_database with owner=dbuser1;
+                        ^
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       | Description 
+------------------+-------------
+ current_database | 
+ db1              | 
+(2 rows)
+
+\c db1;
+SELECT CURRENT_DATABASE;
+ current_database 
+------------------
+ db1
+(1 row)
+
+COMMENT ON DATABASE current_database IS 'db1';
+COMMENT ON DATABASE "current_database" IS 'db2';
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       | Description 
+------------------+-------------
+ current_database | db2
+ db1              | db1
+(2 rows)
+
+-- test alter owner
+ALTER DATABASE current_database OWNER to dbuser2; 
+ALTER DATABASE "current_database" OWNER to dbuser2;
+SELECT d.datname as "Name",
+       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       |  Owner  | Description 
+------------------+---------+-------------
+ current_database | dbuser2 | db2
+ db1              | dbuser2 | db1
+(2 rows)
+
+-- test alter database tablespace
+ALTER DATABASE current_database SET TABLESPACE pg_default;
+ERROR:  cannot change the tablespace of the currently open database
+ALTER DATABASE "current_database" SET TABLESPACE pg_default;
+-- test alter database rename
+ALTER DATABASE current_database rename to db2;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: ALTER DATABASE current_database rename to db2;
+                       ^
+COMMENT ON DATABASE "current_database" IS 'changed from current_database';
+ALTER DATABASE "current_database" rename to db2;
+ALTER DATABASE db2 rename to current_database;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: ALTER DATABASE db2 rename to current_database;
+                                     ^
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1' or d.datname='db2'
+ORDER BY 1;
+ Name |          Description          
+------+-------------------------------
+ db1  | db1
+ db2  | changed from current_database
+(2 rows)
+
+-- test alter database set parameter
+ALTER DATABASE current_database SET parallel_tuple_cost=0.3;
+\c db1
+show parallel_tuple_cost;
+ parallel_tuple_cost 
+---------------------
+ 0.3
+(1 row)
+
+ALTER DATABASE current_database RESET parallel_tuple_cost;
+\c db1
+show parallel_tuple_cost;
+ parallel_tuple_cost 
+---------------------
+ 0.1
+(1 row)
+
+-- clean up
+\c postgres
+DROP DATABASE IF EXISTS "current_database";
+NOTICE:  database "current_database" does not exist, skipping
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db2;
+DROP ROLE dbuser1;
+DROP ROLE dbuser2;
+DROP ROLE dbuser3;
diff --git a/src/test/regress/expected/publication.out b/src/test/regress/expected/publication.out
index b101331..81d8629 100644
--- a/src/test/regress/expected/publication.out
+++ b/src/test/regress/expected/publication.out
@@ -206,6 +206,17 @@ ALTER PUBLICATION testpub2 ADD TABLE testpub_tbl1;  -- ok
 DROP PUBLICATION testpub2;
 SET ROLE regress_publication_user;
 REVOKE CREATE ON DATABASE regression FROM regress_publication_user2;
+--- test grant on database current_database
+GRANT CREATE ON DATABASE CURRENT_DATABASE TO regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- ok
+DROP PUBLICATION testpub2;
+SET ROLE regress_publication_user;
+REVOKE CREATE ON DATABASE CURRENT_DATABASE FROM regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- fail
+ERROR:  permission denied for database regression
+SET ROLE regress_publication_user;
 DROP TABLE testpub_parted;
 DROP VIEW testpub_view;
 DROP TABLE testpub_tbl1;
diff --git a/src/test/regress/expected/rolenames.out b/src/test/regress/expected/rolenames.out
index dce82f5..ab02155 100644
--- a/src/test/regress/expected/rolenames.out
+++ b/src/test/regress/expected/rolenames.out
@@ -369,6 +369,26 @@ SELECT * FROM chksetconfig();
 ----+------+------------+-----------
 (0 rows)
 
+--  ALTER ROLE IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE SET application_name to 'FOO';
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+     db     |       role       |  rolkeyword  |         setconfig         
+------------+------------------+--------------+---------------------------
+ regression | Public           | -            | {application_name=BARBAR}
+ regression | current_user     | -            | {application_name=FOOFOO}
+ regression | regress_testrol2 | current_user | {application_name=FOO}
+(3 rows)
+
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+ db | role | rolkeyword | setconfig 
+----+------+------------+-----------
+(0 rows)
+
 ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ'; -- error
 ERROR:  syntax error at or near "CURRENT_ROLE"
 LINE 1: ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ';
@@ -421,6 +441,26 @@ SELECT * FROM chksetconfig();
 ----+------+------------+-----------
 (0 rows)
 
+--  ALTER USER IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE SET application_name to 'BAR';
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+     db     |       role       |  rolkeyword  |         setconfig         
+------------+------------------+--------------+---------------------------
+ regression | Public           | -            | {application_name=BARBAR}
+ regression | current_user     | -            | {application_name=FOOFOO}
+ regression | regress_testrol1 | session_user | {application_name=BAR}
+(3 rows)
+
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+ db | role | rolkeyword | setconfig 
+----+------+------------+-----------
+(0 rows)
+
 ALTER USER CURRENT_USER SET application_name to 'BAZ'; -- error
 ALTER USER USER SET application_name to 'BOOM'; -- error
 ERROR:  syntax error at or near "USER"
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index e224977..ef69620 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -123,3 +123,4 @@ test: event_trigger
 
 # run stats by itself because its delay may be insufficient under heavy load
 test: stats
+test: dbname
\ No newline at end of file
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 9fc5f1a..5bcb13d 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -186,3 +186,4 @@ test: reloptions
 test: hash_part
 test: event_trigger
 test: stats
+test: dbname
diff --git a/src/test/regress/sql/dbname.sql b/src/test/regress/sql/dbname.sql
new file mode 100644
index 0000000..5c8b36e
--- /dev/null
+++ b/src/test/regress/sql/dbname.sql
@@ -0,0 +1,77 @@
+CREATE ROLE dbuser1 with LOGIN;
+CREATE ROLE dbuser2 with SUPERUSER LOGIN;
+CREATE ROLE dbuser3 with SUPERUSER LOGIN;
+
+DROP DATABASE IF EXISTS db1;
+CREATE DATABASE db1 with owner=dbuser1;
+CREATE DATABASE "current_database" with owner=dbuser1;
+CREATE DATABASE current_database with owner=dbuser1;
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+
+\c db1;
+SELECT CURRENT_DATABASE;
+
+
+COMMENT ON DATABASE current_database IS 'db1';
+COMMENT ON DATABASE "current_database" IS 'db2';
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+-- test alter owner
+ALTER DATABASE current_database OWNER to dbuser2; 
+ALTER DATABASE "current_database" OWNER to dbuser2;
+
+SELECT d.datname as "Name",
+       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+-- test alter database tablespace
+ALTER DATABASE current_database SET TABLESPACE pg_default;
+ALTER DATABASE "current_database" SET TABLESPACE pg_default;
+
+-- test alter database rename
+ALTER DATABASE current_database rename to db2;
+COMMENT ON DATABASE "current_database" IS 'changed from current_database';
+ALTER DATABASE "current_database" rename to db2;
+ALTER DATABASE db2 rename to current_database;
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1' or d.datname='db2'
+ORDER BY 1;
+
+-- test alter database set parameter
+ALTER DATABASE current_database SET parallel_tuple_cost=0.3;
+\c db1
+show parallel_tuple_cost;
+ALTER DATABASE current_database RESET parallel_tuple_cost;
+\c db1
+show parallel_tuple_cost;
+
+-- clean up
+\c postgres
+
+DROP DATABASE IF EXISTS "current_database";
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db2;
+DROP ROLE dbuser1;
+DROP ROLE dbuser2;
+DROP ROLE dbuser3;
diff --git a/src/test/regress/sql/publication.sql b/src/test/regress/sql/publication.sql
index 815410b..0ee3fd3 100644
--- a/src/test/regress/sql/publication.sql
+++ b/src/test/regress/sql/publication.sql
@@ -112,6 +112,18 @@ DROP PUBLICATION testpub2;
 SET ROLE regress_publication_user;
 REVOKE CREATE ON DATABASE regression FROM regress_publication_user2;
 
+--- test grant on database current_database
+GRANT CREATE ON DATABASE CURRENT_DATABASE TO regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- ok
+DROP PUBLICATION testpub2;
+
+SET ROLE regress_publication_user;
+REVOKE CREATE ON DATABASE CURRENT_DATABASE FROM regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- fail
+SET ROLE regress_publication_user;
+
 DROP TABLE testpub_parted;
 DROP VIEW testpub_view;
 DROP TABLE testpub_tbl1;
diff --git a/src/test/regress/sql/rolenames.sql b/src/test/regress/sql/rolenames.sql
index 4c5706b..ff11931 100644
--- a/src/test/regress/sql/rolenames.sql
+++ b/src/test/regress/sql/rolenames.sql
@@ -146,6 +146,15 @@ ALTER ROLE "Public" RESET application_name;
 ALTER ROLE ALL RESET application_name;
 SELECT * FROM chksetconfig();
 
+--  ALTER ROLE IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE SET application_name to 'FOO';
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
 
 ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ'; -- error
 ALTER ROLE USER SET application_name to 'BOOM'; -- error
@@ -170,6 +179,16 @@ ALTER USER ALL RESET application_name;
 SELECT * FROM chksetconfig();
 
 
+--  ALTER USER IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE SET application_name to 'BAR';
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+
 ALTER USER CURRENT_USER SET application_name to 'BAZ'; -- error
 ALTER USER USER SET application_name to 'BOOM'; -- error
 ALTER USER PUBLIC SET application_name to 'BOMB'; -- error

diff --git a/doc/src/sgml/ref/alter_database.sgml b/doc/src/sgml/ref/alter_database.sgml
index 7db878c..48cd840 100644
--- a/doc/src/sgml/ref/alter_database.sgml
+++ b/doc/src/sgml/ref/alter_database.sgml
@@ -31,14 +31,14 @@ ALTER DATABASE <replaceable class="parameter">name</replaceable> [ [ WITH ] <rep
 
 ALTER DATABASE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER DATABASE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER }
 
 ALTER DATABASE <replaceable class="parameter">name</replaceable> SET TABLESPACE <replaceable class="parameter">new_tablespace</replaceable>
 
-ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET <replaceable>configuration_parameter</replaceable>
-ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET ALL
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } RESET <replaceable>configuration_parameter</replaceable>
+ALTER DATABASE { <replaceable class="parameter">name</replaceable> | CURRENT_DATABASE } RESET ALL
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/alter_role.sgml b/doc/src/sgml/ref/alter_role.sgml
index 573a3e8..cf7b575 100644
--- a/doc/src/sgml/ref/alter_role.sgml
+++ b/doc/src/sgml/ref/alter_role.sgml
@@ -38,16 +38,21 @@ ALTER ROLE <replaceable class="parameter">role_specification</replaceable> [ WIT
 
 ALTER ROLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
-ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET ALL
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
+ALTER ROLE { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET ALL
 
 <phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
 
     <replaceable class="parameter">role_name</replaceable>
   | CURRENT_USER
   | SESSION_USER
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/alter_user.sgml b/doc/src/sgml/ref/alter_user.sgml
index 8f50f43..cbf8163 100644
--- a/doc/src/sgml/ref/alter_user.sgml
+++ b/doc/src/sgml/ref/alter_user.sgml
@@ -38,16 +38,21 @@ ALTER USER <replaceable class="parameter">role_specification</replaceable> [ WIT
 
 ALTER USER <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
 
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
-ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_name</replaceable> ] RESET ALL
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET <replaceable>configuration_parameter</replaceable>
+ALTER USER { <replaceable class="parameter">role_specification</replaceable> | ALL } [ IN DATABASE <replaceable class="parameter">database_specification</replaceable> ] RESET ALL
 
 <phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
 
     <replaceable class="parameter">role_name</replaceable>
   | CURRENT_USER
   | SESSION_USER
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 965c5a4..025b672 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -31,7 +31,7 @@ COMMENT ON
   CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
   CONSTRAINT <replaceable class="parameter">constraint_name</replaceable> ON DOMAIN <replaceable class="parameter">domain_name</replaceable> |
   CONVERSION <replaceable class="parameter">object_name</replaceable> |
-  DATABASE <replaceable class="parameter">object_name</replaceable> |
+  DATABASE <replaceable class="parameter">database_specification</replaceable> |
   DOMAIN <replaceable class="parameter">object_name</replaceable> |
   EXTENSION <replaceable class="parameter">object_name</replaceable> |
   EVENT TRIGGER <replaceable class="parameter">object_name</replaceable> |
@@ -73,6 +73,11 @@ COMMENT ON
 * |
 [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] |
 [ [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] ] ORDER BY [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ]
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
@@ -315,6 +320,7 @@ COMMENT ON CONVERSION my_conv IS 'Conversion to UTF8';
 COMMENT ON CONSTRAINT bar_col_cons ON bar IS 'Constrains column col';
 COMMENT ON CONSTRAINT dom_col_constr ON DOMAIN dom IS 'Constrains col of domain';
 COMMENT ON DATABASE my_database IS 'Development Database';
+COMMENT ON DATABASE current_database IS 'Comment on current Database';
 COMMENT ON DOMAIN my_domain IS 'Email Address Domain';
 COMMENT ON EXTENSION hstore IS 'implements the hstore data type';
 COMMENT ON FOREIGN DATA WRAPPER mywrapper IS 'my foreign data wrapper';
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index ff64c7a..880a30d 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -39,9 +39,14 @@ GRANT { { USAGE | SELECT | UPDATE }
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
 
 GRANT { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
-    ON DATABASE <replaceable>database_name</replaceable> [, ...]
+    ON DATABASE <replaceable>database_specification</replaceable> [, ...]
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
 
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
+
 GRANT { USAGE | ALL [ PRIVILEGES ] }
     ON DOMAIN <replaceable>domain_name</replaceable> [, ...]
     TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 7018202..f7a3055 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -46,10 +46,15 @@ REVOKE [ GRANT OPTION FOR ]
 
 REVOKE [ GRANT OPTION FOR ]
     { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
-    ON DATABASE <replaceable>database_name</replaceable> [, ...]
+    ON DATABASE <replaceable>database_specification</replaceable> [, ...]
     FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
     [ CASCADE | RESTRICT ]
 
+<phrase>where <replaceable class="parameter">database_specification</replaceable> can be:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
+
 REVOKE [ GRANT OPTION FOR ]
     { USAGE | ALL [ PRIVILEGES ] }
     ON DOMAIN <replaceable>domain_name</replaceable> [, ...]
diff --git a/doc/src/sgml/ref/security_label.sgml b/doc/src/sgml/ref/security_label.sgml
index e9cfdec..c582c96 100644
--- a/doc/src/sgml/ref/security_label.sgml
+++ b/doc/src/sgml/ref/security_label.sgml
@@ -26,7 +26,7 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
   TABLE <replaceable class="parameter">object_name</replaceable> |
   COLUMN <replaceable class="parameter">table_name</replaceable>.<replaceable class="parameter">column_name</replaceable> |
   AGGREGATE <replaceable class="parameter">aggregate_name</replaceable> ( <replaceable>aggregate_signature</replaceable> ) |
-  DATABASE <replaceable class="parameter">object_name</replaceable> |
+  DATABASE <replaceable class="parameter">database_specification</replaceable> |
   DOMAIN <replaceable class="parameter">object_name</replaceable> |
   EVENT TRIGGER <replaceable class="parameter">object_name</replaceable> |
   FOREIGN TABLE <replaceable class="parameter">object_name</replaceable>
@@ -51,6 +51,11 @@ SECURITY LABEL [ FOR <replaceable class="parameter">provider</replaceable> ] ON
 * |
 [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] |
 [ [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ] ] ORDER BY [ <replaceable>argmode</replaceable> ] [ <replaceable>argname</replaceable> ] <replaceable>argtype</replaceable> [ , ... ]
+
+<phrase>where <replaceable class="parameter">database_specification</replaceable> is:</phrase>
+
+    <replaceable class="parameter">database_name</replaceable>
+  | CURRENT_DATABASE
 </synopsis>
  </refsynopsisdiv>
 
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 1156627..6cc586b 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -65,6 +65,7 @@
 #include "foreign/foreign.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
+#include "nodes/parsenodes.h"
 #include "parser/parse_func.h"
 #include "parser/parse_type.h"
 #include "utils/acl.h"
@@ -657,10 +658,10 @@ objectNamesToOids(ObjectType objtype, List *objnames)
 		case OBJECT_DATABASE:
 			foreach(cell, objnames)
 			{
-				char	   *dbname = strVal(lfirst(cell));
+				DbSpec	   *dbspec = lfirst(cell);
 				Oid			dbid;
 
-				dbid = get_database_oid(dbname, false);
+				dbid = get_dbspec_oid(dbspec,false);
 				objects = lappend_oid(objects, dbid);
 			}
 			break;
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index 570e65a..f415c1d 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -868,6 +868,10 @@ get_object_address(ObjectType objtype, Node *object,
 				}
 				break;
 			case OBJECT_DATABASE:
+				address.classId = DatabaseRelationId;
+				address.objectId = get_dbspec_oid((DbSpec *)object, missing_ok);
+				address.objectSubId = 0;
+				break;
 			case OBJECT_EXTENSION:
 			case OBJECT_TABLESPACE:
 			case OBJECT_ROLE:
@@ -2248,7 +2252,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
 		case OBJECT_DATABASE:
 			if (!pg_database_ownercheck(address.objectId, roleid))
 				aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
-							   strVal((Value *) object));
+							   get_dbspec_name((DbSpec *)object));
 			break;
 		case OBJECT_TYPE:
 		case OBJECT_DOMAIN:
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 0d63866..dd2aab0 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -806,7 +806,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
 	switch (stmt->objectType)
 	{
 		case OBJECT_DATABASE:
-			return AlterDatabaseOwner(strVal((Value *) stmt->object), newowner);
+			return AlterDatabaseOwner((DbSpec *) stmt->object, newowner);
 
 		case OBJECT_SCHEMA:
 			return AlterSchemaOwner(strVal((Value *) stmt->object), newowner);
diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c
index 2f2e69b..64bd07d 100644
--- a/src/backend/commands/comment.c
+++ b/src/backend/commands/comment.c
@@ -52,13 +52,15 @@ CommentObject(CommentStmt *stmt)
 	 */
 	if (stmt->objtype == OBJECT_DATABASE)
 	{
-		char	   *database = strVal((Value *) stmt->object);
-
-		if (!OidIsValid(get_database_oid(database, true)))
+		if (!OidIsValid(get_dbspec_oid((DbSpec *)stmt->object, true)))
 		{
+			char		*dbname = NULL;
+
+			dbname = get_dbspec_name((DbSpec *)stmt->object);
+
 			ereport(WARNING,
 					(errcode(ERRCODE_UNDEFINED_DATABASE),
-					 errmsg("database \"%s\" does not exist", database)));
+					 errmsg("database \"%s\" does not exist", dbname)));
 			return address;
 		}
 	}
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index d2020d0..f50423d 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -1413,6 +1413,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	Datum		new_record[Natts_pg_database];
 	bool		new_record_nulls[Natts_pg_database];
 	bool		new_record_repl[Natts_pg_database];
+	char		*dbname = NULL;
+
+	dbname = get_dbspec_name(stmt->dbspec);
 
 	/* Extract options from the statement node tree */
 	foreach(option, stmt->options)
@@ -1477,7 +1480,7 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 					 parser_errposition(pstate, dtablespace->location)));
 		/* this case isn't allowed within a transaction block */
 		PreventTransactionChain(isTopLevel, "ALTER DATABASE SET TABLESPACE");
-		movedb(stmt->dbname, defGetString(dtablespace));
+		movedb(dbname, defGetString(dtablespace));
 		return InvalidOid;
 	}
 
@@ -1503,20 +1506,20 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	ScanKeyInit(&scankey,
 				Anum_pg_database_datname,
 				BTEqualStrategyNumber, F_NAMEEQ,
-				CStringGetDatum(stmt->dbname));
+				CStringGetDatum(dbname));
 	scan = systable_beginscan(rel, DatabaseNameIndexId, true,
 							  NULL, 1, &scankey);
 	tuple = systable_getnext(scan);
 	if (!HeapTupleIsValid(tuple))
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_DATABASE),
-				 errmsg("database \"%s\" does not exist", stmt->dbname)));
+				 errmsg("database \"%s\" does not exist", dbname)));
 
 	dboid = HeapTupleGetOid(tuple);
 
 	if (!pg_database_ownercheck(HeapTupleGetOid(tuple), GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
-					   stmt->dbname);
+					   dbname);
 
 	/*
 	 * In order to avoid getting locked out and having to go through
@@ -1574,7 +1577,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 Oid
 AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 {
-	Oid			datid = get_database_oid(stmt->dbname, false);
+	Oid			datid;
+
+	datid = get_dbspec_oid(stmt->dbspec, false);
 
 	/*
 	 * Obtain a lock on the database and make sure it didn't go away in the
@@ -1584,7 +1589,7 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 
 	if (!pg_database_ownercheck(datid, GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
-					   stmt->dbname);
+				get_dbspec_name(stmt->dbspec));
 
 	AlterSetting(datid, InvalidOid, stmt->setstmt);
 
@@ -1598,7 +1603,7 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
  * ALTER DATABASE name OWNER TO newowner
  */
 ObjectAddress
-AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
+AlterDatabaseOwner(const DbSpec *dbspec, Oid newOwnerId)
 {
 	Oid			db_id;
 	HeapTuple	tuple;
@@ -1607,6 +1612,9 @@ AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
 	SysScanDesc scan;
 	Form_pg_database datForm;
 	ObjectAddress address;
+	char		*dbname;
+
+	dbname = get_dbspec_name(dbspec);
 
 	/*
 	 * Get the old tuple.  We don't need a lock on the database per se,
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index 71c5caa..6e06a63 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -927,9 +927,9 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 	}
 
 	/* look up and lock the database, if specified */
-	if (stmt->database != NULL)
+	if (stmt->dbspec != NULL)
 	{
-		databaseid = get_database_oid(stmt->database, false);
+		databaseid = get_dbspec_oid(stmt->dbspec,false);
 		shdepLockAndCheckObject(DatabaseRelationId, databaseid);
 
 		if (!stmt->role)
@@ -940,11 +940,11 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 			 */
 			if (!pg_database_ownercheck(databaseid, GetUserId()))
 				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
-							   stmt->database);
+						get_dbspec_name(stmt->dbspec));
 		}
 	}
 
-	if (!stmt->role && !stmt->database)
+	if (!stmt->role && !stmt->dbspec)
 	{
 		/* Must be superuser to alter settings globally. */
 		if (!superuser())
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index f646fd9..2558177 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -2320,6 +2320,7 @@ ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op)
 			*op->resnull = fcinfo.isnull;
 			break;
 		case SVFOP_CURRENT_CATALOG:
+		case SVFOP_CURRENT_DATABASE:
 			InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
 			*op->resvalue = current_database(&fcinfo);
 			*op->resnull = fcinfo.isnull;
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index e5d2de5..5ed8282 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2926,6 +2926,18 @@ _copyTriggerTransition(const TriggerTransition *from)
 	return newnode;
 }
 
+static DbSpec *
+_copyDatabaseSpec(const DbSpec *from)
+{
+	DbSpec   *newnode = makeNode(DbSpec);
+
+	COPY_SCALAR_FIELD(dbtype);
+	COPY_STRING_FIELD(dbname);
+	COPY_LOCATION_FIELD(location);
+
+	return newnode;
+}
+
 static Query *
 _copyQuery(const Query *from)
 {
@@ -3751,7 +3763,7 @@ _copyAlterDatabaseStmt(const AlterDatabaseStmt *from)
 {
 	AlterDatabaseStmt *newnode = makeNode(AlterDatabaseStmt);
 
-	COPY_STRING_FIELD(dbname);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(options);
 
 	return newnode;
@@ -3762,7 +3774,7 @@ _copyAlterDatabaseSetStmt(const AlterDatabaseSetStmt *from)
 {
 	AlterDatabaseSetStmt *newnode = makeNode(AlterDatabaseSetStmt);
 
-	COPY_STRING_FIELD(dbname);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(setstmt);
 
 	return newnode;
@@ -4241,7 +4253,7 @@ _copyAlterRoleSetStmt(const AlterRoleSetStmt *from)
 	AlterRoleSetStmt *newnode = makeNode(AlterRoleSetStmt);
 
 	COPY_NODE_FIELD(role);
-	COPY_STRING_FIELD(database);
+	COPY_NODE_FIELD(dbspec);
 	COPY_NODE_FIELD(setstmt);
 
 	return newnode;
@@ -5568,7 +5580,9 @@ copyObjectImpl(const void *from)
 		case T_PartitionCmd:
 			retval = _copyPartitionCmd(from);
 			break;
-
+		case T_DbSpec:
+			retval = _copyDatabaseSpec(from);
+			break;
 			/*
 			 * MISCELLANEOUS NODES
 			 */
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 785dc54..ac8c375 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1647,7 +1647,7 @@ _equalCreatedbStmt(const CreatedbStmt *a, const CreatedbStmt *b)
 static bool
 _equalAlterDatabaseStmt(const AlterDatabaseStmt *a, const AlterDatabaseStmt *b)
 {
-	COMPARE_STRING_FIELD(dbname);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(options);
 
 	return true;
@@ -1656,7 +1656,7 @@ _equalAlterDatabaseStmt(const AlterDatabaseStmt *a, const AlterDatabaseStmt *b)
 static bool
 _equalAlterDatabaseSetStmt(const AlterDatabaseSetStmt *a, const AlterDatabaseSetStmt *b)
 {
-	COMPARE_STRING_FIELD(dbname);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(setstmt);
 
 	return true;
@@ -2063,7 +2063,7 @@ static bool
 _equalAlterRoleSetStmt(const AlterRoleSetStmt *a, const AlterRoleSetStmt *b)
 {
 	COMPARE_NODE_FIELD(role);
-	COMPARE_STRING_FIELD(database);
+	COMPARE_NODE_FIELD(dbspec);
 	COMPARE_NODE_FIELD(setstmt);
 
 	return true;
@@ -2889,6 +2889,16 @@ _equalPartitionCmd(const PartitionCmd *a, const PartitionCmd *b)
 	return true;
 }
 
+static bool
+_equalDatabaseSpec(const DbSpec *a, const DbSpec *b)
+{
+	COMPARE_SCALAR_FIELD(dbtype);
+	COMPARE_STRING_FIELD(dbname);
+	COMPARE_LOCATION_FIELD(location);
+
+	return true;
+}
+
 /*
  * Stuff from pg_list.h
  */
@@ -3705,6 +3715,9 @@ equal(const void *a, const void *b)
 		case T_PartitionCmd:
 			retval = _equalPartitionCmd(a, b);
 			break;
+		case T_DbSpec:
+			retval = _equalDatabaseSpec(a, b);
+			break;
 
 		default:
 			elog(ERROR, "unrecognized node type: %d",
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 459a227..78a443e 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -187,7 +187,7 @@ static void processCASbits(int cas_bits, int location, const char *constrType,
 			   bool *deferrable, bool *initdeferred, bool *not_valid,
 			   bool *no_inherit, core_yyscan_t yyscanner);
 static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
-
+static DbSpec *makeDbSpec(DbSpecType type, int location);
 %}
 
 %pure-parser
@@ -241,6 +241,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	PartitionSpec		*partspec;
 	PartitionBoundSpec	*partboundspec;
 	RoleSpec			*rolespec;
+	DbSpec				*dbspec;
 }
 
 %type <node>	stmt schema_stmt
@@ -316,7 +317,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 %type <str>		opt_type
 %type <str>		foreign_server_version opt_foreign_server_version
-%type <str>		opt_in_database
+%type <dbspec>		opt_in_database
 
 %type <str>		OptSchemaName
 %type <list>	OptSchemaEltList
@@ -397,7 +398,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				transform_element_list transform_type_list
 				TriggerTransitions TriggerReferencing
 				publication_name_list
-				vacuum_relation_list opt_vacuum_relation_list
+				vacuum_relation_list opt_vacuum_relation_list db_spec_name_list
 
 %type <list>	group_by_list
 %type <node>	group_by_item empty_grouping_set rollup_clause cube_clause
@@ -572,6 +573,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				opt_frame_clause frame_extent frame_bound
 %type <str>		opt_existing_window_name
 %type <boolean> opt_if_not_exists
+%type <dbspec>	db_spec_name
 %type <ival>	generated_when override_kind
 %type <partspec>	PartitionSpec OptPartitionSpec
 %type <str>			part_strategy
@@ -617,7 +619,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	COMMITTED CONCURRENTLY CONFIGURATION CONFLICT CONNECTION CONSTRAINT
 	CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE
 	CROSS CSV CUBE CURRENT_P
-	CURRENT_CATALOG CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
+	CURRENT_CATALOG CURRENT_DATABASE CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
 
 	DATA_P DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
@@ -1156,7 +1158,7 @@ AlterRoleStmt:
 
 opt_in_database:
 			   /* EMPTY */					{ $$ = NULL; }
-			| IN_P DATABASE database_name	{ $$ = $3; }
+			| IN_P DATABASE db_spec_name	{ $$ = $3; }
 		;
 
 AlterRoleSetStmt:
@@ -1164,7 +1166,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->database = $4;
+					n->dbspec = $4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1172,7 +1174,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = NULL;
-					n->database = $4;
+					n->dbspec = $4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1180,7 +1182,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->database = $4;
+					n->dbspec = $4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -1188,7 +1190,7 @@ AlterRoleSetStmt:
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = NULL;
-					n->database = $4;
+					n->dbspec = $4;
 					n->setstmt = $5;
 					$$ = (Node *)n;
 				}
@@ -6425,6 +6427,14 @@ CommentStmt:
 					n->comment = $6;
 					$$ = (Node *) n;
 				}
+			| COMMENT ON DATABASE db_spec_name IS comment_text
+				{
+					CommentStmt *n = makeNode(CommentStmt);
+					n->objtype = OBJECT_DATABASE;
+					n->object = (Node *) $4;
+					n->comment = $6;
+					$$ = (Node *) n;
+				}
 			| COMMENT ON TYPE_P Typename IS comment_text
 				{
 					CommentStmt *n = makeNode(CommentStmt);
@@ -6589,7 +6599,6 @@ comment_type_any_name:
 /* object types taking name */
 comment_type_name:
 			ACCESS METHOD						{ $$ = OBJECT_ACCESS_METHOD; }
-			| DATABASE							{ $$ = OBJECT_DATABASE; }
 			| EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
 			| EXTENSION							{ $$ = OBJECT_EXTENSION; }
 			| FOREIGN DATA_P WRAPPER			{ $$ = OBJECT_FDW; }
@@ -6638,6 +6647,16 @@ SecLabelStmt:
 					n->label = $8;
 					$$ = (Node *) n;
 				}
+			| SECURITY LABEL opt_provider ON DATABASE db_spec_name
+			IS security_label
+				{
+					SecLabelStmt *n = makeNode(SecLabelStmt);
+					n->provider = $3;
+					n->objtype = OBJECT_DATABASE;
+					n->object = (Node *) $6;
+					n->label = $8;
+					$$ = (Node *) n;
+				}
 			| SECURITY LABEL opt_provider ON TYPE_P Typename
 			  IS security_label
 				{
@@ -6726,8 +6745,7 @@ security_label_type_any_name:
 
 /* object types taking name */
 security_label_type_name:
-			DATABASE							{ $$ = OBJECT_DATABASE; }
-			| EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
+			EVENT TRIGGER						{ $$ = OBJECT_EVENT_TRIGGER; }
 			| opt_procedural LANGUAGE			{ $$ = OBJECT_LANGUAGE; }
 			| PUBLICATION						{ $$ = OBJECT_PUBLICATION; }
 			| ROLE								{ $$ = OBJECT_ROLE; }
@@ -7087,7 +7105,7 @@ privilege_target:
 					n->objs = $2;
 					$$ = n;
 				}
-			| DATABASE name_list
+			| DATABASE db_spec_name_list
 				{
 					PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
 					n->targtype = ACL_TARGET_OBJECT;
@@ -9314,11 +9332,11 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
 					n->newowner = $6;
 					$$ = (Node *)n;
 				}
-			| ALTER DATABASE database_name OWNER TO RoleSpec
+			| ALTER DATABASE db_spec_name OWNER TO RoleSpec
 				{
 					AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
 					n->objectType = OBJECT_DATABASE;
-					n->object = (Node *) makeString($3);
+					n->object = (Node *) $3;
 					n->newowner = $6;
 					$$ = (Node *)n;
 				}
@@ -10140,24 +10158,24 @@ opt_equal:	'='										{}
  *****************************************************************************/
 
 AlterDatabaseStmt:
-			ALTER DATABASE database_name WITH createdb_opt_list
+			ALTER DATABASE db_spec_name WITH createdb_opt_list
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = $5;
 					$$ = (Node *)n;
 				 }
-			| ALTER DATABASE database_name createdb_opt_list
+			| ALTER DATABASE db_spec_name createdb_opt_list
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = $4;
 					$$ = (Node *)n;
 				 }
-			| ALTER DATABASE database_name SET TABLESPACE name
+			| ALTER DATABASE db_spec_name SET TABLESPACE name
 				 {
 					AlterDatabaseStmt *n = makeNode(AlterDatabaseStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->options = list_make1(makeDefElem("tablespace",
 														(Node *)makeString($6), @6));
 					$$ = (Node *)n;
@@ -10165,10 +10183,10 @@ AlterDatabaseStmt:
 		;
 
 AlterDatabaseSetStmt:
-			ALTER DATABASE database_name SetResetClause
+			ALTER DATABASE db_spec_name SetResetClause
 				{
 					AlterDatabaseSetStmt *n = makeNode(AlterDatabaseSetStmt);
-					n->dbname = $3;
+					n->dbspec = $3;
 					n->setstmt = $4;
 					$$ = (Node *)n;
 				}
@@ -13692,6 +13710,10 @@ func_expr_common_subexpr:
 				{
 					$$ = makeSQLValueFunction(SVFOP_SESSION_USER, -1, @1);
 				}
+			| CURRENT_DATABASE
+				{
+					$$ = makeSQLValueFunction(SVFOP_CURRENT_DATABASE, -1, @1);
+				}
 			| USER
 				{
 					$$ = makeSQLValueFunction(SVFOP_USER, -1, @1);
@@ -14662,7 +14684,36 @@ name_list:	name
 name:		ColId									{ $$ = $1; };
 
 database_name:
-			ColId									{ $$ = $1; };
+			ColId									{ $$ = $1; }
+			| CURRENT_DATABASE
+				{
+					ereport(ERROR,
+							(errcode(ERRCODE_RESERVED_NAME),
+							 errmsg("%s cannot be used as a database name here",
+									"CURRENT_DATABASE"),
+							 parser_errposition(@1)));
+				}
+		;
+
+db_spec_name_list:	db_spec_name
+					{ $$ = list_make1($1); }
+			| db_spec_name_list ',' db_spec_name
+					{ $$ = lappend($1, $3); }
+		;
+
+
+db_spec_name:
+			ColId
+				{
+					DbSpec *n = makeDbSpec(DBSPEC_CSTRING, @1);
+					n->dbname = pstrdup($1);
+					$$ = n;
+				}
+			| CURRENT_DATABASE
+				{
+					$$ = makeDbSpec(DBSPEC_CURRENT_DATABASE, @1);
+				}
+		;
 
 access_method:
 			ColId									{ $$ = $1; };
@@ -14688,6 +14739,8 @@ func_name:	type_function_name
 						$$ = check_func_name(lcons(makeString($1), $2),
 											 yyscanner);
 					}
+			| CURRENT_DATABASE
+					{ $$ = list_make1(makeString("current_database")); }
 		;
 
 
@@ -15343,6 +15396,7 @@ reserved_keyword:
 			| CONSTRAINT
 			| CREATE
 			| CURRENT_CATALOG
+			| CURRENT_DATABASE
 			| CURRENT_DATE
 			| CURRENT_ROLE
 			| CURRENT_TIME
@@ -16254,6 +16308,20 @@ makeRecursiveViewSelect(char *relname, List *aliases, Node *query)
 	return (Node *) s;
 }
 
+/* makeDbSpec
+ * Create a DbSpec with the given type
+ */
+static DbSpec *
+makeDbSpec(DbSpecType type, int location)
+{
+	DbSpec *spec = makeNode(DbSpec);
+
+	spec->dbtype = type;
+	spec->location = location;
+
+	return spec;
+}
+
 /* parser_init()
  * Initialize to parse one query string
  */
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index b2f5e46..74a0ada 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -2334,6 +2334,7 @@ transformSQLValueFunction(ParseState *pstate, SQLValueFunction *svf)
 		case SVFOP_SESSION_USER:
 		case SVFOP_CURRENT_CATALOG:
 		case SVFOP_CURRENT_SCHEMA:
+		case SVFOP_CURRENT_DATABASE:
 			svf->type = NAMEOID;
 			break;
 	}
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index ea209cd..14cee21 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -1882,6 +1882,9 @@ FigureColnameInternal(Node *node, char **name)
 				case SVFOP_CURRENT_SCHEMA:
 					*name = "current_schema";
 					return 2;
+				case SVFOP_CURRENT_DATABASE:
+					*name = "current_database";
+					return 2;
 			}
 			break;
 		case T_XmlExpr:
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 0cfc297..d90331a 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -24,6 +24,7 @@
 #include "catalog/pg_auth_members.h"
 #include "catalog/pg_type.h"
 #include "catalog/pg_class.h"
+#include "catalog/pg_database.h"
 #include "commands/dbcommands.h"
 #include "commands/proclang.h"
 #include "commands/tablespace.h"
@@ -5273,3 +5274,64 @@ check_rolespec_name(const RoleSpec *role, const char *detail_msg)
 							role->rolename)));
 	}
 }
+
+/*
+ * Given a DbSpec, returns a palloc'ed copy of the corresponding database name.
+ */
+char *
+get_dbspec_name(const DbSpec *db)
+{
+	char	   *dbname;
+	HeapTuple	tuple;
+	Form_pg_database dbForm;
+
+	switch (db->dbtype)
+	{
+		case DBSPEC_CSTRING:
+			Assert(db->dbname);
+			dbname = db->dbname;
+			break;
+
+		case DBSPEC_CURRENT_DATABASE:
+			tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
+			if (!HeapTupleIsValid(tuple))
+				elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
+
+			dbForm = (Form_pg_database) GETSTRUCT(tuple);
+			dbname = pstrdup(NameStr(dbForm->datname));
+			ReleaseSysCache(tuple);
+			break;
+
+		default:
+			elog(ERROR, "unexpected database type %d", db->dbtype);
+	}
+
+	return dbname;
+}
+
+/*
+ * Given a DbSpec node, return the OID it corresponds to.  If missing_ok is
+ * true, return InvalidOid if the database does not exist.
+ */
+Oid
+get_dbspec_oid(const DbSpec *db, bool missing_ok)
+{
+	Oid			oid;
+
+	switch (db->dbtype)
+	{
+		case DBSPEC_CSTRING:
+			Assert(db->dbname);
+			oid = get_database_oid(db->dbname, missing_ok);
+			break;
+
+		case DBSPEC_CURRENT_DATABASE:
+			oid = MyDatabaseId;
+			break;
+
+		default:
+			elog(ERROR, "unexpected database type %d", db->dbtype);
+	}
+
+	return oid;
+}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index c5f5a1c..bdc5cd3 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8360,6 +8360,10 @@ get_rule_expr(Node *node, deparse_context *context,
 					case SVFOP_CURRENT_SCHEMA:
 						appendStringInfoString(buf, "CURRENT_SCHEMA");
 						break;
+					case SVFOP_CURRENT_DATABASE:
+						appendStringInfoString(buf, "CURRENT_DATABASE");
+						break;
+
 				}
 			}
 			break;
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index 677c7fc..a08e99d 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -24,7 +24,7 @@ extern void dropdb(const char *dbname, bool missing_ok);
 extern ObjectAddress RenameDatabase(const char *oldname, const char *newname);
 extern Oid	AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel);
 extern Oid	AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
-extern ObjectAddress AlterDatabaseOwner(const char *dbname, Oid newOwnerId);
+extern ObjectAddress AlterDatabaseOwner(const DbSpec *dbspec, Oid newOwnerId);
 
 extern Oid	get_database_oid(const char *dbname, bool missingok);
 extern char *get_database_name(Oid dbid);
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 74b094a..62b2938 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -464,6 +464,7 @@ typedef enum NodeTag
 	T_OnConflictClause,
 	T_CommonTableExpr,
 	T_RoleSpec,
+	T_DbSpec,
 	T_TriggerTransition,
 	T_PartitionElem,
 	T_PartitionSpec,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index bbacbe1..ef2cfa4 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -330,6 +330,23 @@ typedef struct RoleSpec
 } RoleSpec;
 
 /*
+ * DbSpecType - The type of a database name.
+ */
+typedef enum DbSpecType
+{
+	DBSPEC_CSTRING,				/* database name is stored as a C string */
+	DBSPEC_CURRENT_DATABASE		/* database name is CURRENT_DATABASE */
+} DbSpecType;
+
+typedef struct DbSpec
+{
+	NodeTag			type;
+	DbSpecType		dbtype;			/* Type of the database */
+	char			*dbname;		/* filled only for DBSPEC_CSTRING */
+	int				location;		/* token location, or -1 if unknown */
+} DbSpec;
+
+/*
  * FuncCall - a function or aggregate invocation
  *
  * agg_order (if not NIL) indicates we saw 'foo(... ORDER BY ...)', or if
@@ -2440,7 +2457,7 @@ typedef struct AlterRoleSetStmt
 {
 	NodeTag		type;
 	RoleSpec   *role;			/* role */
-	char	   *database;		/* database name, or NULL */
+	DbSpec	   *dbspec;			/* name of database to set */
 	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterRoleSetStmt;
 
@@ -3050,14 +3067,14 @@ typedef struct CreatedbStmt
 typedef struct AlterDatabaseStmt
 {
 	NodeTag		type;
-	char	   *dbname;			/* name of database to alter */
-	List	   *options;		/* List of DefElem nodes */
+	DbSpec		*dbspec;		/* name of database to alter */
+	List	   	*options;		/* List of DefElem nodes */
 } AlterDatabaseStmt;
 
 typedef struct AlterDatabaseSetStmt
 {
 	NodeTag		type;
-	char	   *dbname;			/* database name */
+	DbSpec		*dbspec;			/* DbSpec */
 	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterDatabaseSetStmt;
 
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 1b4b0d7..efc1a9c 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1102,7 +1102,8 @@ typedef enum SQLValueFunctionOp
 	SVFOP_USER,
 	SVFOP_SESSION_USER,
 	SVFOP_CURRENT_CATALOG,
-	SVFOP_CURRENT_SCHEMA
+	SVFOP_CURRENT_SCHEMA,
+	SVFOP_CURRENT_DATABASE
 } SQLValueFunctionOp;
 
 typedef struct SQLValueFunction
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 26af944..fb706d0 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -105,6 +105,7 @@ PG_KEYWORD("csv", CSV, UNRESERVED_KEYWORD)
 PG_KEYWORD("cube", CUBE, UNRESERVED_KEYWORD)
 PG_KEYWORD("current", CURRENT_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("current_catalog", CURRENT_CATALOG, RESERVED_KEYWORD)
+PG_KEYWORD("current_database", CURRENT_DATABASE, RESERVED_KEYWORD)
 PG_KEYWORD("current_date", CURRENT_DATE, RESERVED_KEYWORD)
 PG_KEYWORD("current_role", CURRENT_ROLE, RESERVED_KEYWORD)
 PG_KEYWORD("current_schema", CURRENT_SCHEMA, TYPE_FUNC_NAME_KEYWORD)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index f4d4be8..7422c8e 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -215,6 +215,8 @@ extern Oid	get_rolespec_oid(const RoleSpec *role, bool missing_ok);
 extern void check_rolespec_name(const RoleSpec *role, const char *detail_msg);
 extern HeapTuple get_rolespec_tuple(const RoleSpec *role);
 extern char *get_rolespec_name(const RoleSpec *role);
+extern char *get_dbspec_name(const DbSpec *db);
+extern Oid  get_dbspec_oid(const DbSpec *db, bool missing_ok);
 
 extern void select_best_grantor(Oid roleId, AclMode privileges,
 					const Acl *acl, Oid ownerId,
diff --git a/src/test/regress/expected/dbname.out b/src/test/regress/expected/dbname.out
new file mode 100644
index 0000000..cac34de
--- /dev/null
+++ b/src/test/regress/expected/dbname.out
@@ -0,0 +1,113 @@
+CREATE ROLE dbuser1 with LOGIN;
+CREATE ROLE dbuser2 with SUPERUSER LOGIN;
+CREATE ROLE dbuser3 with SUPERUSER LOGIN;
+DROP DATABASE IF EXISTS db1;
+NOTICE:  database "db1" does not exist, skipping
+CREATE DATABASE db1 with owner=dbuser1;
+CREATE DATABASE "current_database" with owner=dbuser1;
+CREATE DATABASE current_database with owner=dbuser1;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: CREATE DATABASE current_database with owner=dbuser1;
+                        ^
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       | Description 
+------------------+-------------
+ current_database | 
+ db1              | 
+(2 rows)
+
+\c db1;
+SELECT CURRENT_DATABASE;
+ current_database 
+------------------
+ db1
+(1 row)
+
+COMMENT ON DATABASE current_database IS 'db1';
+COMMENT ON DATABASE "current_database" IS 'db2';
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       | Description 
+------------------+-------------
+ current_database | db2
+ db1              | db1
+(2 rows)
+
+-- test alter owner
+ALTER DATABASE current_database OWNER to dbuser2; 
+ALTER DATABASE "current_database" OWNER to dbuser2;
+SELECT d.datname as "Name",
+       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+       Name       |  Owner  | Description 
+------------------+---------+-------------
+ current_database | dbuser2 | db2
+ db1              | dbuser2 | db1
+(2 rows)
+
+-- test alter database tablespace
+ALTER DATABASE current_database SET TABLESPACE pg_default;
+ERROR:  cannot change the tablespace of the currently open database
+ALTER DATABASE "current_database" SET TABLESPACE pg_default;
+-- test alter database rename
+ALTER DATABASE current_database rename to db2;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: ALTER DATABASE current_database rename to db2;
+                       ^
+COMMENT ON DATABASE "current_database" IS 'changed from current_database';
+ALTER DATABASE "current_database" rename to db2;
+ALTER DATABASE db2 rename to current_database;
+ERROR:  CURRENT_DATABASE cannot be used as a database name here
+LINE 1: ALTER DATABASE db2 rename to current_database;
+                                     ^
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1' or d.datname='db2'
+ORDER BY 1;
+ Name |          Description          
+------+-------------------------------
+ db1  | db1
+ db2  | changed from current_database
+(2 rows)
+
+-- test alter database set parameter
+ALTER DATABASE current_database SET parallel_tuple_cost=0.3;
+\c db1
+show parallel_tuple_cost;
+ parallel_tuple_cost 
+---------------------
+ 0.3
+(1 row)
+
+ALTER DATABASE current_database RESET parallel_tuple_cost;
+\c db1
+show parallel_tuple_cost;
+ parallel_tuple_cost 
+---------------------
+ 0.1
+(1 row)
+
+-- clean up
+\c postgres
+DROP DATABASE IF EXISTS "current_database";
+NOTICE:  database "current_database" does not exist, skipping
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db2;
+DROP ROLE dbuser1;
+DROP ROLE dbuser2;
+DROP ROLE dbuser3;
diff --git a/src/test/regress/expected/publication.out b/src/test/regress/expected/publication.out
index 0c86c64..2dfb69a 100644
--- a/src/test/regress/expected/publication.out
+++ b/src/test/regress/expected/publication.out
@@ -206,6 +206,17 @@ ALTER PUBLICATION testpub2 ADD TABLE testpub_tbl1;  -- ok
 DROP PUBLICATION testpub2;
 SET ROLE regress_publication_user;
 REVOKE CREATE ON DATABASE regression FROM regress_publication_user2;
+--- test grant on database current_database
+GRANT CREATE ON DATABASE CURRENT_DATABASE TO regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- ok
+DROP PUBLICATION testpub2;
+SET ROLE regress_publication_user;
+REVOKE CREATE ON DATABASE CURRENT_DATABASE FROM regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- fail
+ERROR:  permission denied for database regression
+SET ROLE regress_publication_user;
 DROP TABLE testpub_parted;
 DROP VIEW testpub_view;
 DROP TABLE testpub_tbl1;
diff --git a/src/test/regress/expected/rolenames.out b/src/test/regress/expected/rolenames.out
index dce82f5..ab02155 100644
--- a/src/test/regress/expected/rolenames.out
+++ b/src/test/regress/expected/rolenames.out
@@ -369,6 +369,26 @@ SELECT * FROM chksetconfig();
 ----+------+------------+-----------
 (0 rows)
 
+--  ALTER ROLE IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE SET application_name to 'FOO';
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+     db     |       role       |  rolkeyword  |         setconfig         
+------------+------------------+--------------+---------------------------
+ regression | Public           | -            | {application_name=BARBAR}
+ regression | current_user     | -            | {application_name=FOOFOO}
+ regression | regress_testrol2 | current_user | {application_name=FOO}
+(3 rows)
+
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+ db | role | rolkeyword | setconfig 
+----+------+------------+-----------
+(0 rows)
+
 ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ'; -- error
 ERROR:  syntax error at or near "CURRENT_ROLE"
 LINE 1: ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ';
@@ -421,6 +441,26 @@ SELECT * FROM chksetconfig();
 ----+------+------------+-----------
 (0 rows)
 
+--  ALTER USER IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE SET application_name to 'BAR';
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+     db     |       role       |  rolkeyword  |         setconfig         
+------------+------------------+--------------+---------------------------
+ regression | Public           | -            | {application_name=BARBAR}
+ regression | current_user     | -            | {application_name=FOOFOO}
+ regression | regress_testrol1 | session_user | {application_name=BAR}
+(3 rows)
+
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+ db | role | rolkeyword | setconfig 
+----+------+------------+-----------
+(0 rows)
+
 ALTER USER CURRENT_USER SET application_name to 'BAZ'; -- error
 ALTER USER USER SET application_name to 'BOOM'; -- error
 ERROR:  syntax error at or near "USER"
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index ad9434f..0b31579 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -123,3 +123,4 @@ test: event_trigger
 
 # run stats by itself because its delay may be insufficient under heavy load
 test: stats
+test: dbname
\ No newline at end of file
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 27cd498..d2c6830 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -187,3 +187,4 @@ test: hash_part
 test: indexing
 test: event_trigger
 test: stats
+test: dbname
diff --git a/src/test/regress/sql/dbname.sql b/src/test/regress/sql/dbname.sql
new file mode 100644
index 0000000..5c8b36e
--- /dev/null
+++ b/src/test/regress/sql/dbname.sql
@@ -0,0 +1,77 @@
+CREATE ROLE dbuser1 with LOGIN;
+CREATE ROLE dbuser2 with SUPERUSER LOGIN;
+CREATE ROLE dbuser3 with SUPERUSER LOGIN;
+
+DROP DATABASE IF EXISTS db1;
+CREATE DATABASE db1 with owner=dbuser1;
+CREATE DATABASE "current_database" with owner=dbuser1;
+CREATE DATABASE current_database with owner=dbuser1;
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+
+\c db1;
+SELECT CURRENT_DATABASE;
+
+
+COMMENT ON DATABASE current_database IS 'db1';
+COMMENT ON DATABASE "current_database" IS 'db2';
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+-- test alter owner
+ALTER DATABASE current_database OWNER to dbuser2; 
+ALTER DATABASE "current_database" OWNER to dbuser2;
+
+SELECT d.datname as "Name",
+       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1'
+ORDER BY 1;
+
+-- test alter database tablespace
+ALTER DATABASE current_database SET TABLESPACE pg_default;
+ALTER DATABASE "current_database" SET TABLESPACE pg_default;
+
+-- test alter database rename
+ALTER DATABASE current_database rename to db2;
+COMMENT ON DATABASE "current_database" IS 'changed from current_database';
+ALTER DATABASE "current_database" rename to db2;
+ALTER DATABASE db2 rename to current_database;
+
+SELECT d.datname as "Name",
+       pg_catalog.shobj_description(d.oid, 'pg_database') as "Description"
+FROM pg_catalog.pg_database d
+  	JOIN pg_catalog.pg_tablespace t on d.dattablespace = t.oid
+WHERE d.datname='current_database' or d.datname='db1' or d.datname='db2'
+ORDER BY 1;
+
+-- test alter database set parameter
+ALTER DATABASE current_database SET parallel_tuple_cost=0.3;
+\c db1
+show parallel_tuple_cost;
+ALTER DATABASE current_database RESET parallel_tuple_cost;
+\c db1
+show parallel_tuple_cost;
+
+-- clean up
+\c postgres
+
+DROP DATABASE IF EXISTS "current_database";
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db2;
+DROP ROLE dbuser1;
+DROP ROLE dbuser2;
+DROP ROLE dbuser3;
diff --git a/src/test/regress/sql/publication.sql b/src/test/regress/sql/publication.sql
index 815410b..0ee3fd3 100644
--- a/src/test/regress/sql/publication.sql
+++ b/src/test/regress/sql/publication.sql
@@ -112,6 +112,18 @@ DROP PUBLICATION testpub2;
 SET ROLE regress_publication_user;
 REVOKE CREATE ON DATABASE regression FROM regress_publication_user2;
 
+--- test grant on database current_database
+GRANT CREATE ON DATABASE CURRENT_DATABASE TO regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- ok
+DROP PUBLICATION testpub2;
+
+SET ROLE regress_publication_user;
+REVOKE CREATE ON DATABASE CURRENT_DATABASE FROM regress_publication_user2;
+SET ROLE regress_publication_user2;
+CREATE PUBLICATION testpub2;  -- fail
+SET ROLE regress_publication_user;
+
 DROP TABLE testpub_parted;
 DROP VIEW testpub_view;
 DROP TABLE testpub_tbl1;
diff --git a/src/test/regress/sql/rolenames.sql b/src/test/regress/sql/rolenames.sql
index 4c5706b..ff11931 100644
--- a/src/test/regress/sql/rolenames.sql
+++ b/src/test/regress/sql/rolenames.sql
@@ -146,6 +146,15 @@ ALTER ROLE "Public" RESET application_name;
 ALTER ROLE ALL RESET application_name;
 SELECT * FROM chksetconfig();
 
+--  ALTER ROLE IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE SET application_name to 'FOO';
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+ALTER ROLE CURRENT_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER ROLE "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
 
 ALTER ROLE CURRENT_ROLE SET application_name to 'BAZ'; -- error
 ALTER ROLE USER SET application_name to 'BOOM'; -- error
@@ -170,6 +179,16 @@ ALTER USER ALL RESET application_name;
 SELECT * FROM chksetconfig();
 
 
+--  ALTER USER IN DATABASE CURRENT_DATABASE SET/RESET
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE SET application_name to 'BAR';
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE SET application_name to 'FOOFOO';
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE SET application_name to 'BARBAR';
+SELECT * FROM chksetconfig();
+ALTER USER SESSION_USER IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "current_user" IN DATABASE CURRENT_DATABASE RESET application_name;
+ALTER USER "Public" IN DATABASE CURRENT_DATABASE RESET application_name;
+SELECT * FROM chksetconfig();
+
 ALTER USER CURRENT_USER SET application_name to 'BAZ'; -- error
 ALTER USER USER SET application_name to 'BOOM'; -- error
 ALTER USER PUBLIC SET application_name to 'BOMB'; -- error