[Patch] Adding CORRESPONDING/CORRESPONDING BY to set operation

From d20300c7d5467b56d9316df30f0ba1473a36d314 Mon Sep 17 00:00:00 2001
From: alanruijia <alanmao94@gmail.com>
Date: Thu, 25 Jul 2019 16:28:37 -0700
Subject: [PATCH v1] Patch: Add CORRESPONDING/CORRESPONDING BY to set operation
To: hackers
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="------------2.21.0"

This is a multi-part message in MIME format.
--------------2.21.0
Content-Type: text/plain; charset=UTF-8; format=fixed
Content-Transfer-Encoding: 8bit


diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 06d611b64c..67bc60a1b0 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -40,7 +40,7 @@ SELECT [ ALL | DISTINCT [ ON ( <replaceable class="parameter">expression</replac
     [ GROUP BY <replaceable class="parameter">grouping_element</replaceable> [, ...] ]
     [ HAVING <replaceable class="parameter">condition</replaceable> [, ...] ]
     [ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceable class="parameter">window_definition</replaceable> ) [, ...] ]
-    [ { UNION | INTERSECT | EXCEPT } [ ALL | DISTINCT ] <replaceable class="parameter">select</replaceable> ]
+    [ { UNION | INTERSECT | EXCEPT } [ ALL | DISTINCT ]  [CORRESPONDING [ BY ( <replaceable>column</replaceable> [, ...] ) ] ] <replaceable class="parameter">select</replaceable> ]
     [ ORDER BY <replaceable class="parameter">expression</replaceable> [ ASC | DESC | USING <replaceable class="parameter">operator</replaceable> ] [ NULLS { FIRST | LAST } ] [, ...] ]
     [ LIMIT { <replaceable class="parameter">count</replaceable> | ALL } ]
     [ OFFSET <replaceable class="parameter">start</replaceable> [ ROW | ROWS ] ]
@@ -163,7 +163,11 @@ TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ]
       strictly in both result sets.  The <literal>EXCEPT</literal>
       operator returns the rows that are in the first result set but
       not in the second.  In all three cases, duplicate rows are
-      eliminated unless <literal>ALL</literal> is specified.  The noise
+      eliminated unless <literal>ALL</literal> is specified.
+      With <literal>CORRESPONDING</literal> by itself, only columns
+      with matching names and types are returned.
+      With <literal>CORRESPONDING BY (column1, ... )</literal>,
+      only the specified columns are returned.  The noise
       word <literal>DISTINCT</literal> can be added to explicitly specify
       eliminating duplicate rows.  Notice that <literal>DISTINCT</literal> is
       the default behavior here, even though <literal>ALL</literal> is
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 4f2ebe5118..a130ecbb38 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1055,6 +1055,7 @@ _equalSelectStmt(const SelectStmt *a, const SelectStmt *b)
 	COMPARE_SCALAR_FIELD(all);
 	COMPARE_NODE_FIELD(larg);
 	COMPARE_NODE_FIELD(rarg);
+	COMPARE_NODE_FIELD(correspondingClause);
 
 	return true;
 }
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 86c31a48c9..46a160bcd1 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2703,6 +2703,7 @@ _outSelectStmt(StringInfo str, const SelectStmt *node)
 	WRITE_NODE_FIELD(lockingClause);
 	WRITE_NODE_FIELD(withClause);
 	WRITE_ENUM_FIELD(op, SetOperation);
+	WRITE_NODE_FIELD(correspondingClause);
 	WRITE_BOOL_FIELD(all);
 	WRITE_NODE_FIELD(larg);
 	WRITE_NODE_FIELD(rarg);
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 85d7a96406..4c77260d22 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -64,6 +64,9 @@ static Query *transformValuesClause(ParseState *pstate, SelectStmt *stmt);
 static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
 static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
 									   bool isTopLevel, List **targetlist);
+static void trimSetOperationStatement(SetOperationStmt *sostmt, SetOperationStmt *topstmt);
+static void trimCorrespondingTargetList(List **larg_tlist, List **rarg_tlist, List *correspondingClause);
+static void trimPasrseStateRangeTbl(ParseState *pstate, List *targetList);
 static void determineRecursiveColTypes(ParseState *pstate,
 									   Node *larg, List *nrtargetlist);
 static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
@@ -1589,6 +1592,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 			   *lcm,
 			   *lcc,
 			   *l;
+	List	   *targetList;
 	List	   *targetvars,
 			   *targetnames,
 			   *sv_namespace;
@@ -1657,8 +1661,12 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 	 * Recursively transform the components of the tree.
 	 */
 	sostmt = castNode(SetOperationStmt,
-					  transformSetOperationTree(pstate, stmt, true, NULL));
+					  transformSetOperationTree(pstate, stmt, true, &targetList));
 	Assert(sostmt);
+	if (stmt->correspondingClause != NIL) {
+		trimSetOperationStatement(sostmt, NULL);
+		trimPasrseStateRangeTbl(pstate, targetList);
+	}
 	qry->setOperations = (Node *) sostmt;
 
 	/*
@@ -1683,39 +1691,74 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 	 * have one that corresponds to a real RT entry; else funny things may
 	 * happen when the tree is mashed by rule rewriting.
 	 */
-	qry->targetList = NIL;
-	targetvars = NIL;
-	targetnames = NIL;
+	if (stmt->correspondingClause == NIL) {
+		qry->targetList = NIL;
+		targetvars = NIL;
+		targetnames = NIL;
+		forfour(lct, sostmt->colTypes,
+				lcm, sostmt->colTypmods,
+				lcc, sostmt->colCollations,
+				left_tlist, leftmostQuery->targetList)
+		{
+			Oid			colType = lfirst_oid(lct);
+			int32		colTypmod = lfirst_int(lcm);
+			Oid			colCollation = lfirst_oid(lcc);
+			TargetEntry *lefttle = (TargetEntry *) lfirst(left_tlist);
+			char	   *colName;
+			TargetEntry *tle;
+			Var		   *var;
 
-	forfour(lct, sostmt->colTypes,
-			lcm, sostmt->colTypmods,
-			lcc, sostmt->colCollations,
-			left_tlist, leftmostQuery->targetList)
-	{
-		Oid			colType = lfirst_oid(lct);
-		int32		colTypmod = lfirst_int(lcm);
-		Oid			colCollation = lfirst_oid(lcc);
-		TargetEntry *lefttle = (TargetEntry *) lfirst(left_tlist);
-		char	   *colName;
-		TargetEntry *tle;
-		Var		   *var;
+			Assert(!lefttle->resjunk);
+			colName = pstrdup(lefttle->resname);
+			var = makeVar(leftmostRTI,
+						  lefttle->resno,
+						  colType,
+						  colTypmod,
+						  colCollation,
+						  0);
+			var->location = exprLocation((Node *) lefttle->expr);
+			tle = makeTargetEntry((Expr *) var,
+								  (AttrNumber) pstate->p_next_resno++,
+								  colName,
+								  false);
+			qry->targetList = lappend(qry->targetList, tle);
+			targetvars = lappend(targetvars, var);
+			targetnames = lappend(targetnames, makeString(colName));
+		}
+	} else {
+		qry->targetList = NIL;
+		targetvars = NIL;
+		targetnames = NIL;
+		forfour(lct, sostmt->colTypes,
+				lcm, sostmt->colTypmods,
+				lcc, sostmt->colCollations,
+				left_tlist, targetList)
+		{
+			Oid			colType = lfirst_oid(lct);
+			int32		colTypmod = lfirst_int(lcm);
+			Oid			colCollation = lfirst_oid(lcc);
+			TargetEntry *lefttle = (TargetEntry *) lfirst(left_tlist);
+			char	   *colName;
+			TargetEntry *tle;
+			Var		   *var;
 
-		Assert(!lefttle->resjunk);
-		colName = pstrdup(lefttle->resname);
-		var = makeVar(leftmostRTI,
-					  lefttle->resno,
-					  colType,
-					  colTypmod,
-					  colCollation,
-					  0);
-		var->location = exprLocation((Node *) lefttle->expr);
-		tle = makeTargetEntry((Expr *) var,
-							  (AttrNumber) pstate->p_next_resno++,
-							  colName,
-							  false);
-		qry->targetList = lappend(qry->targetList, tle);
-		targetvars = lappend(targetvars, var);
-		targetnames = lappend(targetnames, makeString(colName));
+			Assert(!lefttle->resjunk);
+			colName = pstrdup(lefttle->resname);
+			var = makeVar(leftmostRTI,
+						  lefttle->resno,
+						  colType,
+						  colTypmod,
+						  colCollation,
+						  0);
+			var->location = exprLocation((Node *) lefttle->expr);
+			tle = makeTargetEntry((Expr *) var,
+								  (AttrNumber) pstate->p_next_resno++,
+								  colName,
+								  false);
+			qry->targetList = lappend(qry->targetList, tle);
+			targetvars = lappend(targetvars, var);
+			targetnames = lappend(targetnames, makeString(colName));
+		}
 	}
 
 	/*
@@ -1986,7 +2029,11 @@ transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
 		/*
 		 * Verify that the two children have the same number of non-junk
 		 * columns, and determine the types of the merged output columns.
+		 * For CORRESPONDING clause, verify that the 
 		 */
+		if (stmt->correspondingClause != NIL) {
+			trimCorrespondingTargetList(&ltargetlist, &rtargetlist, stmt->correspondingClause);
+		}
 		if (list_length(ltargetlist) != list_length(rtargetlist))
 			ereport(ERROR,
 					(errcode(ERRCODE_SYNTAX_ERROR),
@@ -2137,16 +2184,20 @@ transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
 			 */
 			if (targetlist)
 			{
-				SetToDefault *rescolnode = makeNode(SetToDefault);
+				char	   *colName;
 				TargetEntry *restle;
+				Var		   *var;
 
-				rescolnode->typeId = rescoltype;
-				rescolnode->typeMod = rescoltypmod;
-				rescolnode->collation = rescolcoll;
-				rescolnode->location = bestlocation;
-				restle = makeTargetEntry((Expr *) rescolnode,
-										 0, /* no need to set resno */
-										 NULL,
+				colName = pstrdup(ltle->resname);
+				var = makeVar(((Var *)lcolnode)->varno,
+							  ltle->resno,
+							  rescoltype,
+							  rescoltypmod,
+							  rescolcoll,
+							  bestlocation);
+				restle = makeTargetEntry(var,
+										 ltle->resno,
+										 colName,
 										 false);
 				*targetlist = lappend(*targetlist, restle);
 			}
@@ -2156,6 +2207,170 @@ transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
 	}
 }
 
+static void trimCorrespondingTargetList(List **larg_tlist, List **rarg_tlist, List *correspondingClause)
+{
+	List	   *tlist = NIL;
+	ListCell   *itlc,
+		   *ltlc,
+		   *rtlc,
+		   *ctlc;
+	TargetEntry *tle;
+	List	   *lmatchingTargetList = NIL;
+	List	   *rmatchingTargetList = NIL;
+
+	if (linitial(correspondingClause) == NULL) {
+		int resno = 1;
+		foreach(ltlc, *larg_tlist) {
+			foreach(rtlc, *rarg_tlist) {
+				TargetEntry *ltle = (TargetEntry *) lfirst(ltlc);
+				TargetEntry *rtle = (TargetEntry *) lfirst(rtlc);
+
+				Assert(ltle->resname != NULL);
+				Assert(rtle->resname != NULL);
+
+				if(strcmp(ltle->resname, rtle->resname) == 0) {
+					ltle->resno = resno;
+					rtle->resno = resno;
+					resno++;
+					lmatchingTargetList = lappend(lmatchingTargetList, ltle);
+					rmatchingTargetList = lappend(rmatchingTargetList, rtle);
+					continue;
+				}
+			}
+		}
+		*larg_tlist = lmatchingTargetList;
+		*rarg_tlist = rmatchingTargetList;
+	} else {
+		int lresno = 1, rresno = 1;
+		foreach (ctlc, correspondingClause) {
+			Node* ctle = lfirst(ctlc);
+			if (IsA(ctle, String)) {
+				char *name = strVal(ctle);
+				foreach(ltlc, *larg_tlist) {
+					TargetEntry *ltle = (TargetEntry *) lfirst(ltlc);
+					Assert(ltle->resname != NULL);
+					if(strcmp(ltle->resname, name) == 0) {
+						ltle->resno = lresno;
+						lresno++;
+						lmatchingTargetList = lappend(lmatchingTargetList, ltle);
+						continue;
+					}
+				}
+				foreach(rtlc, *rarg_tlist) {
+					TargetEntry *rtle = (TargetEntry *) lfirst(rtlc);
+					Assert(rtle->resname != NULL);
+					if(strcmp(rtle->resname, name) == 0) {
+						rtle->resno = rresno;
+						rresno++;
+						rmatchingTargetList = lappend(rmatchingTargetList, rtle);
+						continue;
+					}
+				}
+				if (rresno != lresno) {
+					ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
+									errmsg("CORRESPONDING BY clause must only contain column names from both tables.")));
+				}
+			} else {
+				ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
+								errmsg(
+								"CORRESPONDING BY clause must have only column names and not constants or ordinals in the column name list."
+								)));
+			}
+		}
+		*larg_tlist = lmatchingTargetList;
+		*rarg_tlist = rmatchingTargetList;
+	}
+	
+	if(list_length(*larg_tlist) == 0 || list_length(*rarg_tlist) == 0) {
+		ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
+						errmsg("CORRESPONDING/CORRESPONDING BY clause must have at least one column name in both of the queries or in BY clause."
+						)));
+	}
+
+}
+
+static void trimSetOperationStatement(SetOperationStmt *sostmt, SetOperationStmt *topstmt) {
+	if (topstmt != NULL) {
+		sostmt->colTypes = list_copy(topstmt->colTypes);
+		sostmt->colTypmods = list_copy(topstmt->colTypmods);
+		sostmt->colCollations = list_copy(topstmt->colCollations);
+	}
+	if (sostmt->larg && IsA(sostmt->larg, SetOperationStmt))
+		trimSetOperationStatement(sostmt->larg, sostmt);
+	if (sostmt->rarg && IsA(sostmt->rarg, SetOperationStmt))
+		trimSetOperationStatement(sostmt->rarg, sostmt);
+}
+
+static void trimPasrseStateRangeTbl(ParseState *pstate, List *ref_tlist)
+{
+	ListCell   *rtc,
+		   *itlc,
+		   *rtlc;
+	foreach (rtc, pstate->p_rtable)
+	{
+		RangeTblEntry *rte = (RangeTblEntry *) lfirst(rtc);
+		int 		resno = 1;
+		List	   *tlist = NIL;
+		char selectName[32];
+		Alias	   *eref;
+		int			numaliases;
+		int			varattno;
+		ListCell   *tlistitem;
+		char	   *refname = rte->alias->aliasname;
+		foreach(rtlc, ref_tlist)
+		{
+			foreach(itlc, rte->subquery->targetList)
+			{
+				TargetEntry *itle = (TargetEntry *) lfirst(itlc);
+				TargetEntry *rtle = (TargetEntry *) lfirst(rtlc);
+				TargetEntry *tle;
+
+				Assert(itle->resname != NULL);
+				Assert(rtle->resname != NULL);
+
+				if(strcmp(itle->resname, rtle->resname) == 0) {
+					tle = makeTargetEntry((Expr *) itle->expr,
+								  (AttrNumber) resno++,
+								  pstrdup(itle->resname),
+								  false);
+					tle->ressortgroupref = tle->resno;
+					tlist = lappend(tlist, tle);
+					continue;
+				}
+			}
+		}
+		rte->subquery->targetList = tlist;
+		eref = copyObject(rte->alias);
+		numaliases = list_length(eref->colnames);
+
+		/* fill in any unspecified alias columns */
+		varattno = 0;
+		foreach(tlistitem, rte->subquery->targetList)
+		{
+			TargetEntry *te = (TargetEntry *) lfirst(tlistitem);
+
+			if (te->resjunk)
+				continue;
+			varattno++;
+			Assert(varattno == te->resno);
+			if (varattno > numaliases)
+			{
+				char	   *attrname;
+
+				attrname = pstrdup(te->resname);
+				eref->colnames = lappend(eref->colnames, makeString(attrname));
+			}
+		}
+		if (varattno < numaliases)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+					 errmsg("table \"%s\" has %d columns available but %d columns specified",
+							refname, varattno, numaliases)));
+
+		rte->eref = eref;
+	}
+}
+
 /*
  * Process the outputs of the non-recursive term of a recursive union
  * to set up the parent CTE's columns
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c97bb367f8..979480bdc4 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -167,7 +167,7 @@ static void insertSelectOptions(SelectStmt *stmt,
 								Node *limitOffset, Node *limitCount,
 								WithClause *withClause,
 								core_yyscan_t yyscanner);
-static Node *makeSetOp(SetOperation op, bool all, Node *larg, Node *rarg);
+static Node *makeSetOp(SetOperation op, bool all, Node *larg, Node *rarg, List * correspondingClause);
 static Node *doNegate(Node *n, int location);
 static void doNegateFloat(Value *v);
 static Node *makeAndExpr(Node *lexpr, Node *rexpr, int location);
@@ -406,6 +406,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				TriggerTransitions TriggerReferencing
 				publication_name_list
 				vacuum_relation_list opt_vacuum_relation_list
+				opt_corresponding_clause
 
 %type <list>	group_by_list
 %type <node>	group_by_item empty_grouping_set rollup_clause cube_clause
@@ -623,7 +624,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	CHARACTER CHARACTERISTICS CHECK CHECKPOINT CLASS CLOSE
 	CLUSTER COALESCE COLLATE COLLATION COLUMN COLUMNS COMMENT COMMENTS COMMIT
 	COMMITTED CONCURRENTLY CONFIGURATION CONFLICT CONNECTION CONSTRAINT
-	CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE
+	CONSTRAINTS CONTENT_P CONTINUE_P CONVERSION_P COPY CORRESPONDING COST CREATE
 	CROSS CSV CUBE CURRENT_P
 	CURRENT_CATALOG CURRENT_DATE CURRENT_ROLE CURRENT_SCHEMA
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
@@ -11357,20 +11358,26 @@ simple_select:
 					n->fromClause = list_make1($2);
 					$$ = (Node *)n;
 				}
-			| select_clause UNION all_or_distinct select_clause
+			| select_clause UNION all_or_distinct opt_corresponding_clause select_clause
 				{
-					$$ = makeSetOp(SETOP_UNION, $3, $1, $4);
+					$$ = makeSetOp(SETOP_UNION, $3, $1, $5, $4);
 				}
-			| select_clause INTERSECT all_or_distinct select_clause
+			| select_clause INTERSECT all_or_distinct opt_corresponding_clause select_clause
 				{
-					$$ = makeSetOp(SETOP_INTERSECT, $3, $1, $4);
+					$$ = makeSetOp(SETOP_INTERSECT, $3, $1, $5, $4);
 				}
-			| select_clause EXCEPT all_or_distinct select_clause
+			| select_clause EXCEPT all_or_distinct opt_corresponding_clause select_clause
 				{
-					$$ = makeSetOp(SETOP_EXCEPT, $3, $1, $4);
+					$$ = makeSetOp(SETOP_EXCEPT, $3, $1, $5, $4);
 				}
 		;
 
+opt_corresponding_clause:
+			CORRESPONDING BY '(' name_list ')'		{ $$ = $4; }
+			| CORRESPONDING							{ $$ = list_make1(NIL); }
+			| /*EMPTY*/								{ $$ = NIL; }
+			;
+
 /*
  * SQL standard WITH clause looks like:
  *
@@ -15063,6 +15070,7 @@ unreserved_keyword:
 			| CONTINUE_P
 			| CONVERSION_P
 			| COPY
+			| CORRESPONDING
 			| COST
 			| CSV
 			| CUBE
@@ -15906,7 +15914,7 @@ insertSelectOptions(SelectStmt *stmt,
 }
 
 static Node *
-makeSetOp(SetOperation op, bool all, Node *larg, Node *rarg)
+makeSetOp(SetOperation op, bool all, Node *larg, Node *rarg, List * correspondingClause)
 {
 	SelectStmt *n = makeNode(SelectStmt);
 
@@ -15914,6 +15922,7 @@ makeSetOp(SetOperation op, bool all, Node *larg, Node *rarg)
 	n->all = all;
 	n->larg = (SelectStmt *) larg;
 	n->rarg = (SelectStmt *) rarg;
+	n->correspondingClause = correspondingClause;
 	return (Node *) n;
 }
 
diff --git a/src/backend/parser/parse_type.c b/src/backend/parser/parse_type.c
index 9de5e0680d..b3ee0fc0e7 100644
--- a/src/backend/parser/parse_type.c
+++ b/src/backend/parser/parse_type.c
@@ -769,7 +769,8 @@ typeStringToTypeName(const char *str)
 		stmt->limitCount != NULL ||
 		stmt->lockingClause != NIL ||
 		stmt->withClause != NULL ||
-		stmt->op != SETOP_NONE)
+		stmt->op != SETOP_NONE ||
+		stmt->correspondingClause != NIL)
 		goto fail;
 	if (list_length(stmt->targetList) != 1)
 		goto fail;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 94ded3c135..3d5585bb7d 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1605,6 +1605,7 @@ typedef struct SelectStmt
 	bool		all;			/* ALL specified? */
 	struct SelectStmt *larg;	/* left child */
 	struct SelectStmt *rarg;	/* right child */
+	List	   *correspondingClause;
 	/* Eventually add fields for CORRESPONDING spec here */
 } SelectStmt;
 
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 00ace8425e..50622591d9 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -97,6 +97,7 @@ PG_KEYWORD("content", CONTENT_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("continue", CONTINUE_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("conversion", CONVERSION_P, UNRESERVED_KEYWORD)
 PG_KEYWORD("copy", COPY, UNRESERVED_KEYWORD)
+PG_KEYWORD("corresponding", CORRESPONDING, UNRESERVED_KEYWORD)
 PG_KEYWORD("cost", COST, UNRESERVED_KEYWORD)
 PG_KEYWORD("create", CREATE, RESERVED_KEYWORD)
 PG_KEYWORD("cross", CROSS, TYPE_FUNC_NAME_KEYWORD)

--------------2.21.0--