Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3114 insertions, 0 deletions

diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
new file mode 100644
index 0000000..8ef5a1e
--- /dev/null
+++ b/src/backend/parser/parse_expr.c
@@ -0,0 +1,3114 @@
+/*-------------------------------------------------------------------------
+ *
+ * parse_expr.c
+ *	  handle expressions in parser
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/parser/parse_expr.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "catalog/pg_type.h"
+#include "commands/dbcommands.h"
+#include "miscadmin.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "optimizer/optimizer.h"
+#include "parser/analyze.h"
+#include "parser/parse_agg.h"
+#include "parser/parse_clause.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_collate.h"
+#include "parser/parse_expr.h"
+#include "parser/parse_func.h"
+#include "parser/parse_oper.h"
+#include "parser/parse_relation.h"
+#include "parser/parse_target.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/date.h"
+#include "utils/lsyscache.h"
+#include "utils/timestamp.h"
+#include "utils/xml.h"
+
+/* GUC parameters */
+bool		Transform_null_equals = false;
+
+
+static Node *transformExprRecurse(ParseState *pstate, Node *expr);
+static Node *transformParamRef(ParseState *pstate, ParamRef *pref);
+static Node *transformAExprOp(ParseState *pstate, A_Expr *a);
+static Node *transformAExprOpAny(ParseState *pstate, A_Expr *a);
+static Node *transformAExprOpAll(ParseState *pstate, A_Expr *a);
+static Node *transformAExprDistinct(ParseState *pstate, A_Expr *a);
+static Node *transformAExprNullIf(ParseState *pstate, A_Expr *a);
+static Node *transformAExprIn(ParseState *pstate, A_Expr *a);
+static Node *transformAExprBetween(ParseState *pstate, A_Expr *a);
+static Node *transformBoolExpr(ParseState *pstate, BoolExpr *a);
+static Node *transformFuncCall(ParseState *pstate, FuncCall *fn);
+static Node *transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref);
+static Node *transformCaseExpr(ParseState *pstate, CaseExpr *c);
+static Node *transformSubLink(ParseState *pstate, SubLink *sublink);
+static Node *transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
+								Oid array_type, Oid element_type, int32 typmod);
+static Node *transformRowExpr(ParseState *pstate, RowExpr *r, bool allowDefault);
+static Node *transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c);
+static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
+static Node *transformSQLValueFunction(ParseState *pstate,
+									   SQLValueFunction *svf);
+static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
+static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
+static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
+static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
+static Node *transformColumnRef(ParseState *pstate, ColumnRef *cref);
+static Node *transformWholeRowRef(ParseState *pstate,
+								  ParseNamespaceItem *nsitem,
+								  int sublevels_up, int location);
+static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
+static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
+static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *make_row_comparison_op(ParseState *pstate, List *opname,
+									List *largs, List *rargs, int location);
+static Node *make_row_distinct_op(ParseState *pstate, List *opname,
+								  RowExpr *lrow, RowExpr *rrow, int location);
+static Expr *make_distinct_op(ParseState *pstate, List *opname,
+							  Node *ltree, Node *rtree, int location);
+static Node *make_nulltest_from_distinct(ParseState *pstate,
+										 A_Expr *distincta, Node *arg);
+
+
+/*
+ * transformExpr -
+ *	  Analyze and transform expressions. Type checking and type casting is
+ *	  done here.  This processing converts the raw grammar output into
+ *	  expression trees with fully determined semantics.
+ */
+Node *
+transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind)
+{
+	Node	   *result;
+	ParseExprKind sv_expr_kind;
+
+	/* Save and restore identity of expression type we're parsing */
+	Assert(exprKind != EXPR_KIND_NONE);
+	sv_expr_kind = pstate->p_expr_kind;
+	pstate->p_expr_kind = exprKind;
+
+	result = transformExprRecurse(pstate, expr);
+
+	pstate->p_expr_kind = sv_expr_kind;
+
+	return result;
+}
+
+static Node *
+transformExprRecurse(ParseState *pstate, Node *expr)
+{
+	Node	   *result;
+
+	if (expr == NULL)
+		return NULL;
+
+	/* Guard against stack overflow due to overly complex expressions */
+	check_stack_depth();
+
+	switch (nodeTag(expr))
+	{
+		case T_ColumnRef:
+			result = transformColumnRef(pstate, (ColumnRef *) expr);
+			break;
+
+		case T_ParamRef:
+			result = transformParamRef(pstate, (ParamRef *) expr);
+			break;
+
+		case T_A_Const:
+			{
+				A_Const    *con = (A_Const *) expr;
+				Value	   *val = &con->val;
+
+				result = (Node *) make_const(pstate, val, con->location);
+				break;
+			}
+
+		case T_A_Indirection:
+			result = transformIndirection(pstate, (A_Indirection *) expr);
+			break;
+
+		case T_A_ArrayExpr:
+			result = transformArrayExpr(pstate, (A_ArrayExpr *) expr,
+										InvalidOid, InvalidOid, -1);
+			break;
+
+		case T_TypeCast:
+			result = transformTypeCast(pstate, (TypeCast *) expr);
+			break;
+
+		case T_CollateClause:
+			result = transformCollateClause(pstate, (CollateClause *) expr);
+			break;
+
+		case T_A_Expr:
+			{
+				A_Expr	   *a = (A_Expr *) expr;
+
+				switch (a->kind)
+				{
+					case AEXPR_OP:
+						result = transformAExprOp(pstate, a);
+						break;
+					case AEXPR_OP_ANY:
+						result = transformAExprOpAny(pstate, a);
+						break;
+					case AEXPR_OP_ALL:
+						result = transformAExprOpAll(pstate, a);
+						break;
+					case AEXPR_DISTINCT:
+					case AEXPR_NOT_DISTINCT:
+						result = transformAExprDistinct(pstate, a);
+						break;
+					case AEXPR_NULLIF:
+						result = transformAExprNullIf(pstate, a);
+						break;
+					case AEXPR_IN:
+						result = transformAExprIn(pstate, a);
+						break;
+					case AEXPR_LIKE:
+					case AEXPR_ILIKE:
+					case AEXPR_SIMILAR:
+						/* we can transform these just like AEXPR_OP */
+						result = transformAExprOp(pstate, a);
+						break;
+					case AEXPR_BETWEEN:
+					case AEXPR_NOT_BETWEEN:
+					case AEXPR_BETWEEN_SYM:
+					case AEXPR_NOT_BETWEEN_SYM:
+						result = transformAExprBetween(pstate, a);
+						break;
+					default:
+						elog(ERROR, "unrecognized A_Expr kind: %d", a->kind);
+						result = NULL;	/* keep compiler quiet */
+						break;
+				}
+				break;
+			}
+
+		case T_BoolExpr:
+			result = transformBoolExpr(pstate, (BoolExpr *) expr);
+			break;
+
+		case T_FuncCall:
+			result = transformFuncCall(pstate, (FuncCall *) expr);
+			break;
+
+		case T_MultiAssignRef:
+			result = transformMultiAssignRef(pstate, (MultiAssignRef *) expr);
+			break;
+
+		case T_GroupingFunc:
+			result = transformGroupingFunc(pstate, (GroupingFunc *) expr);
+			break;
+
+		case T_NamedArgExpr:
+			{
+				NamedArgExpr *na = (NamedArgExpr *) expr;
+
+				na->arg = (Expr *) transformExprRecurse(pstate, (Node *) na->arg);
+				result = expr;
+				break;
+			}
+
+		case T_SubLink:
+			result = transformSubLink(pstate, (SubLink *) expr);
+			break;
+
+		case T_CaseExpr:
+			result = transformCaseExpr(pstate, (CaseExpr *) expr);
+			break;
+
+		case T_RowExpr:
+			result = transformRowExpr(pstate, (RowExpr *) expr, false);
+			break;
+
+		case T_CoalesceExpr:
+			result = transformCoalesceExpr(pstate, (CoalesceExpr *) expr);
+			break;
+
+		case T_MinMaxExpr:
+			result = transformMinMaxExpr(pstate, (MinMaxExpr *) expr);
+			break;
+
+		case T_SQLValueFunction:
+			result = transformSQLValueFunction(pstate,
+											   (SQLValueFunction *) expr);
+			break;
+
+		case T_XmlExpr:
+			result = transformXmlExpr(pstate, (XmlExpr *) expr);
+			break;
+
+		case T_XmlSerialize:
+			result = transformXmlSerialize(pstate, (XmlSerialize *) expr);
+			break;
+
+		case T_NullTest:
+			{
+				NullTest   *n = (NullTest *) expr;
+
+				n->arg = (Expr *) transformExprRecurse(pstate, (Node *) n->arg);
+				/* the argument can be any type, so don't coerce it */
+				n->argisrow = type_is_rowtype(exprType((Node *) n->arg));
+				result = expr;
+				break;
+			}
+
+		case T_BooleanTest:
+			result = transformBooleanTest(pstate, (BooleanTest *) expr);
+			break;
+
+		case T_CurrentOfExpr:
+			result = transformCurrentOfExpr(pstate, (CurrentOfExpr *) expr);
+			break;
+
+			/*
+			 * In all places where DEFAULT is legal, the caller should have
+			 * processed it rather than passing it to transformExpr().
+			 */
+		case T_SetToDefault:
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("DEFAULT is not allowed in this context"),
+					 parser_errposition(pstate,
+										((SetToDefault *) expr)->location)));
+			break;
+
+			/*
+			 * CaseTestExpr doesn't require any processing; it is only
+			 * injected into parse trees in a fully-formed state.
+			 *
+			 * Ordinarily we should not see a Var here, but it is convenient
+			 * for transformJoinUsingClause() to create untransformed operator
+			 * trees containing already-transformed Vars.  The best
+			 * alternative would be to deconstruct and reconstruct column
+			 * references, which seems expensively pointless.  So allow it.
+			 */
+		case T_CaseTestExpr:
+		case T_Var:
+			{
+				result = (Node *) expr;
+				break;
+			}
+
+		default:
+			/* should not reach here */
+			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
+			result = NULL;		/* keep compiler quiet */
+			break;
+	}
+
+	return result;
+}
+
+/*
+ * helper routine for delivering "column does not exist" error message
+ *
+ * (Usually we don't have to work this hard, but the general case of field
+ * selection from an arbitrary node needs it.)
+ */
+static void
+unknown_attribute(ParseState *pstate, Node *relref, const char *attname,
+				  int location)
+{
+	RangeTblEntry *rte;
+
+	if (IsA(relref, Var) &&
+		((Var *) relref)->varattno == InvalidAttrNumber)
+	{
+		/* Reference the RTE by alias not by actual table name */
+		rte = GetRTEByRangeTablePosn(pstate,
+									 ((Var *) relref)->varno,
+									 ((Var *) relref)->varlevelsup);
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_COLUMN),
+				 errmsg("column %s.%s does not exist",
+						rte->eref->aliasname, attname),
+				 parser_errposition(pstate, location)));
+	}
+	else
+	{
+		/* Have to do it by reference to the type of the expression */
+		Oid			relTypeId = exprType(relref);
+
+		if (ISCOMPLEX(relTypeId))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column \"%s\" not found in data type %s",
+							attname, format_type_be(relTypeId)),
+					 parser_errposition(pstate, location)));
+		else if (relTypeId == RECORDOID)
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("could not identify column \"%s\" in record data type",
+							attname),
+					 parser_errposition(pstate, location)));
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("column notation .%s applied to type %s, "
+							"which is not a composite type",
+							attname, format_type_be(relTypeId)),
+					 parser_errposition(pstate, location)));
+	}
+}
+
+static Node *
+transformIndirection(ParseState *pstate, A_Indirection *ind)
+{
+	Node	   *last_srf = pstate->p_last_srf;
+	Node	   *result = transformExprRecurse(pstate, ind->arg);
+	List	   *subscripts = NIL;
+	int			location = exprLocation(result);
+	ListCell   *i;
+
+	/*
+	 * We have to split any field-selection operations apart from
+	 * subscripting.  Adjacent A_Indices nodes have to be treated as a single
+	 * multidimensional subscript operation.
+	 */
+	foreach(i, ind->indirection)
+	{
+		Node	   *n = lfirst(i);
+
+		if (IsA(n, A_Indices))
+			subscripts = lappend(subscripts, n);
+		else if (IsA(n, A_Star))
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("row expansion via \"*\" is not supported here"),
+					 parser_errposition(pstate, location)));
+		}
+		else
+		{
+			Node	   *newresult;
+
+			Assert(IsA(n, String));
+
+			/* process subscripts before this field selection */
+			if (subscripts)
+				result = (Node *) transformContainerSubscripts(pstate,
+															   result,
+															   exprType(result),
+															   exprTypmod(result),
+															   subscripts,
+															   false);
+			subscripts = NIL;
+
+			newresult = ParseFuncOrColumn(pstate,
+										  list_make1(n),
+										  list_make1(result),
+										  last_srf,
+										  NULL,
+										  false,
+										  location);
+			if (newresult == NULL)
+				unknown_attribute(pstate, result, strVal(n), location);
+			result = newresult;
+		}
+	}
+	/* process trailing subscripts, if any */
+	if (subscripts)
+		result = (Node *) transformContainerSubscripts(pstate,
+													   result,
+													   exprType(result),
+													   exprTypmod(result),
+													   subscripts,
+													   false);
+
+	return result;
+}
+
+/*
+ * Transform a ColumnRef.
+ *
+ * If you find yourself changing this code, see also ExpandColumnRefStar.
+ */
+static Node *
+transformColumnRef(ParseState *pstate, ColumnRef *cref)
+{
+	Node	   *node = NULL;
+	char	   *nspname = NULL;
+	char	   *relname = NULL;
+	char	   *colname = NULL;
+	ParseNamespaceItem *nsitem;
+	int			levels_up;
+	enum
+	{
+		CRERR_NO_COLUMN,
+		CRERR_NO_RTE,
+		CRERR_WRONG_DB,
+		CRERR_TOO_MANY
+	}			crerr = CRERR_NO_COLUMN;
+	const char *err;
+
+	/*
+	 * Check to see if the column reference is in an invalid place within the
+	 * query.  We allow column references in most places, except in default
+	 * expressions and partition bound expressions.
+	 */
+	err = NULL;
+	switch (pstate->p_expr_kind)
+	{
+		case EXPR_KIND_NONE:
+			Assert(false);		/* can't happen */
+			break;
+		case EXPR_KIND_OTHER:
+		case EXPR_KIND_JOIN_ON:
+		case EXPR_KIND_JOIN_USING:
+		case EXPR_KIND_FROM_SUBSELECT:
+		case EXPR_KIND_FROM_FUNCTION:
+		case EXPR_KIND_WHERE:
+		case EXPR_KIND_POLICY:
+		case EXPR_KIND_HAVING:
+		case EXPR_KIND_FILTER:
+		case EXPR_KIND_WINDOW_PARTITION:
+		case EXPR_KIND_WINDOW_ORDER:
+		case EXPR_KIND_WINDOW_FRAME_RANGE:
+		case EXPR_KIND_WINDOW_FRAME_ROWS:
+		case EXPR_KIND_WINDOW_FRAME_GROUPS:
+		case EXPR_KIND_SELECT_TARGET:
+		case EXPR_KIND_INSERT_TARGET:
+		case EXPR_KIND_UPDATE_SOURCE:
+		case EXPR_KIND_UPDATE_TARGET:
+		case EXPR_KIND_GROUP_BY:
+		case EXPR_KIND_ORDER_BY:
+		case EXPR_KIND_DISTINCT_ON:
+		case EXPR_KIND_LIMIT:
+		case EXPR_KIND_OFFSET:
+		case EXPR_KIND_RETURNING:
+		case EXPR_KIND_VALUES:
+		case EXPR_KIND_VALUES_SINGLE:
+		case EXPR_KIND_CHECK_CONSTRAINT:
+		case EXPR_KIND_DOMAIN_CHECK:
+		case EXPR_KIND_FUNCTION_DEFAULT:
+		case EXPR_KIND_INDEX_EXPRESSION:
+		case EXPR_KIND_INDEX_PREDICATE:
+		case EXPR_KIND_STATS_EXPRESSION:
+		case EXPR_KIND_ALTER_COL_TRANSFORM:
+		case EXPR_KIND_EXECUTE_PARAMETER:
+		case EXPR_KIND_TRIGGER_WHEN:
+		case EXPR_KIND_PARTITION_EXPRESSION:
+		case EXPR_KIND_CALL_ARGUMENT:
+		case EXPR_KIND_COPY_WHERE:
+		case EXPR_KIND_GENERATED_COLUMN:
+		case EXPR_KIND_CYCLE_MARK:
+			/* okay */
+			break;
+
+		case EXPR_KIND_COLUMN_DEFAULT:
+			err = _("cannot use column reference in DEFAULT expression");
+			break;
+		case EXPR_KIND_PARTITION_BOUND:
+			err = _("cannot use column reference in partition bound expression");
+			break;
+
+			/*
+			 * There is intentionally no default: case here, so that the
+			 * compiler will warn if we add a new ParseExprKind without
+			 * extending this switch.  If we do see an unrecognized value at
+			 * runtime, the behavior will be the same as for EXPR_KIND_OTHER,
+			 * which is sane anyway.
+			 */
+	}
+	if (err)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg_internal("%s", err),
+				 parser_errposition(pstate, cref->location)));
+
+	/*
+	 * Give the PreParseColumnRefHook, if any, first shot.  If it returns
+	 * non-null then that's all, folks.
+	 */
+	if (pstate->p_pre_columnref_hook != NULL)
+	{
+		node = pstate->p_pre_columnref_hook(pstate, cref);
+		if (node != NULL)
+			return node;
+	}
+
+	/*----------
+	 * The allowed syntaxes are:
+	 *
+	 * A		First try to resolve as unqualified column name;
+	 *			if no luck, try to resolve as unqualified table name (A.*).
+	 * A.B		A is an unqualified table name; B is either a
+	 *			column or function name (trying column name first).
+	 * A.B.C	schema A, table B, col or func name C.
+	 * A.B.C.D	catalog A, schema B, table C, col or func D.
+	 * A.*		A is an unqualified table name; means whole-row value.
+	 * A.B.*	whole-row value of table B in schema A.
+	 * A.B.C.*	whole-row value of table C in schema B in catalog A.
+	 *
+	 * We do not need to cope with bare "*"; that will only be accepted by
+	 * the grammar at the top level of a SELECT list, and transformTargetList
+	 * will take care of it before it ever gets here.  Also, "A.*" etc will
+	 * be expanded by transformTargetList if they appear at SELECT top level,
+	 * so here we are only going to see them as function or operator inputs.
+	 *
+	 * Currently, if a catalog name is given then it must equal the current
+	 * database name; we check it here and then discard it.
+	 *----------
+	 */
+	switch (list_length(cref->fields))
+	{
+		case 1:
+			{
+				Node	   *field1 = (Node *) linitial(cref->fields);
+
+				Assert(IsA(field1, String));
+				colname = strVal(field1);
+
+				/* Try to identify as an unqualified column */
+				node = colNameToVar(pstate, colname, false, cref->location);
+
+				if (node == NULL)
+				{
+					/*
+					 * Not known as a column of any range-table entry.
+					 *
+					 * Try to find the name as a relation.  Note that only
+					 * relations already entered into the rangetable will be
+					 * recognized.
+					 *
+					 * This is a hack for backwards compatibility with
+					 * PostQUEL-inspired syntax.  The preferred form now is
+					 * "rel.*".
+					 */
+					nsitem = refnameNamespaceItem(pstate, NULL, colname,
+												  cref->location,
+												  &levels_up);
+					if (nsitem)
+						node = transformWholeRowRef(pstate, nsitem, levels_up,
+													cref->location);
+				}
+				break;
+			}
+		case 2:
+			{
+				Node	   *field1 = (Node *) linitial(cref->fields);
+				Node	   *field2 = (Node *) lsecond(cref->fields);
+
+				Assert(IsA(field1, String));
+				relname = strVal(field1);
+
+				/* Locate the referenced nsitem */
+				nsitem = refnameNamespaceItem(pstate, nspname, relname,
+											  cref->location,
+											  &levels_up);
+				if (nsitem == NULL)
+				{
+					crerr = CRERR_NO_RTE;
+					break;
+				}
+
+				/* Whole-row reference? */
+				if (IsA(field2, A_Star))
+				{
+					node = transformWholeRowRef(pstate, nsitem, levels_up,
+												cref->location);
+					break;
+				}
+
+				Assert(IsA(field2, String));
+				colname = strVal(field2);
+
+				/* Try to identify as a column of the nsitem */
+				node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
+										   cref->location);
+				if (node == NULL)
+				{
+					/* Try it as a function call on the whole row */
+					node = transformWholeRowRef(pstate, nsitem, levels_up,
+												cref->location);
+					node = ParseFuncOrColumn(pstate,
+											 list_make1(makeString(colname)),
+											 list_make1(node),
+											 pstate->p_last_srf,
+											 NULL,
+											 false,
+											 cref->location);
+				}
+				break;
+			}
+		case 3:
+			{
+				Node	   *field1 = (Node *) linitial(cref->fields);
+				Node	   *field2 = (Node *) lsecond(cref->fields);
+				Node	   *field3 = (Node *) lthird(cref->fields);
+
+				Assert(IsA(field1, String));
+				nspname = strVal(field1);
+				Assert(IsA(field2, String));
+				relname = strVal(field2);
+
+				/* Locate the referenced nsitem */
+				nsitem = refnameNamespaceItem(pstate, nspname, relname,
+											  cref->location,
+											  &levels_up);
+				if (nsitem == NULL)
+				{
+					crerr = CRERR_NO_RTE;
+					break;
+				}
+
+				/* Whole-row reference? */
+				if (IsA(field3, A_Star))
+				{
+					node = transformWholeRowRef(pstate, nsitem, levels_up,
+												cref->location);
+					break;
+				}
+
+				Assert(IsA(field3, String));
+				colname = strVal(field3);
+
+				/* Try to identify as a column of the nsitem */
+				node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
+										   cref->location);
+				if (node == NULL)
+				{
+					/* Try it as a function call on the whole row */
+					node = transformWholeRowRef(pstate, nsitem, levels_up,
+												cref->location);
+					node = ParseFuncOrColumn(pstate,
+											 list_make1(makeString(colname)),
+											 list_make1(node),
+											 pstate->p_last_srf,
+											 NULL,
+											 false,
+											 cref->location);
+				}
+				break;
+			}
+		case 4:
+			{
+				Node	   *field1 = (Node *) linitial(cref->fields);
+				Node	   *field2 = (Node *) lsecond(cref->fields);
+				Node	   *field3 = (Node *) lthird(cref->fields);
+				Node	   *field4 = (Node *) lfourth(cref->fields);
+				char	   *catname;
+
+				Assert(IsA(field1, String));
+				catname = strVal(field1);
+				Assert(IsA(field2, String));
+				nspname = strVal(field2);
+				Assert(IsA(field3, String));
+				relname = strVal(field3);
+
+				/*
+				 * We check the catalog name and then ignore it.
+				 */
+				if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+				{
+					crerr = CRERR_WRONG_DB;
+					break;
+				}
+
+				/* Locate the referenced nsitem */
+				nsitem = refnameNamespaceItem(pstate, nspname, relname,
+											  cref->location,
+											  &levels_up);
+				if (nsitem == NULL)
+				{
+					crerr = CRERR_NO_RTE;
+					break;
+				}
+
+				/* Whole-row reference? */
+				if (IsA(field4, A_Star))
+				{
+					node = transformWholeRowRef(pstate, nsitem, levels_up,
+												cref->location);
+					break;
+				}
+
+				Assert(IsA(field4, String));
+				colname = strVal(field4);
+
+				/* Try to identify as a column of the nsitem */
+				node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
+										   cref->location);
+				if (node == NULL)
+				{
+					/* Try it as a function call on the whole row */
+					node = transformWholeRowRef(pstate, nsitem, levels_up,
+												cref->location);
+					node = ParseFuncOrColumn(pstate,
+											 list_make1(makeString(colname)),
+											 list_make1(node),
+											 pstate->p_last_srf,
+											 NULL,
+											 false,
+											 cref->location);
+				}
+				break;
+			}
+		default:
+			crerr = CRERR_TOO_MANY; /* too many dotted names */
+			break;
+	}
+
+	/*
+	 * Now give the PostParseColumnRefHook, if any, a chance.  We pass the
+	 * translation-so-far so that it can throw an error if it wishes in the
+	 * case that it has a conflicting interpretation of the ColumnRef. (If it
+	 * just translates anyway, we'll throw an error, because we can't undo
+	 * whatever effects the preceding steps may have had on the pstate.) If it
+	 * returns NULL, use the standard translation, or throw a suitable error
+	 * if there is none.
+	 */
+	if (pstate->p_post_columnref_hook != NULL)
+	{
+		Node	   *hookresult;
+
+		hookresult = pstate->p_post_columnref_hook(pstate, cref, node);
+		if (node == NULL)
+			node = hookresult;
+		else if (hookresult != NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_AMBIGUOUS_COLUMN),
+					 errmsg("column reference \"%s\" is ambiguous",
+							NameListToString(cref->fields)),
+					 parser_errposition(pstate, cref->location)));
+	}
+
+	/*
+	 * Throw error if no translation found.
+	 */
+	if (node == NULL)
+	{
+		switch (crerr)
+		{
+			case CRERR_NO_COLUMN:
+				errorMissingColumn(pstate, relname, colname, cref->location);
+				break;
+			case CRERR_NO_RTE:
+				errorMissingRTE(pstate, makeRangeVar(nspname, relname,
+													 cref->location));
+				break;
+			case CRERR_WRONG_DB:
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cross-database references are not implemented: %s",
+								NameListToString(cref->fields)),
+						 parser_errposition(pstate, cref->location)));
+				break;
+			case CRERR_TOO_MANY:
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("improper qualified name (too many dotted names): %s",
+								NameListToString(cref->fields)),
+						 parser_errposition(pstate, cref->location)));
+				break;
+		}
+	}
+
+	return node;
+}
+
+static Node *
+transformParamRef(ParseState *pstate, ParamRef *pref)
+{
+	Node	   *result;
+
+	/*
+	 * The core parser knows nothing about Params.  If a hook is supplied,
+	 * call it.  If not, or if the hook returns NULL, throw a generic error.
+	 */
+	if (pstate->p_paramref_hook != NULL)
+		result = pstate->p_paramref_hook(pstate, pref);
+	else
+		result = NULL;
+
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_PARAMETER),
+				 errmsg("there is no parameter $%d", pref->number),
+				 parser_errposition(pstate, pref->location)));
+
+	return result;
+}
+
+/* Test whether an a_expr is a plain NULL constant or not */
+static bool
+exprIsNullConstant(Node *arg)
+{
+	if (arg && IsA(arg, A_Const))
+	{
+		A_Const    *con = (A_Const *) arg;
+
+		if (con->val.type == T_Null)
+			return true;
+	}
+	return false;
+}
+
+static Node *
+transformAExprOp(ParseState *pstate, A_Expr *a)
+{
+	Node	   *lexpr = a->lexpr;
+	Node	   *rexpr = a->rexpr;
+	Node	   *result;
+
+	/*
+	 * Special-case "foo = NULL" and "NULL = foo" for compatibility with
+	 * standards-broken products (like Microsoft's).  Turn these into IS NULL
+	 * exprs. (If either side is a CaseTestExpr, then the expression was
+	 * generated internally from a CASE-WHEN expression, and
+	 * transform_null_equals does not apply.)
+	 */
+	if (Transform_null_equals &&
+		list_length(a->name) == 1 &&
+		strcmp(strVal(linitial(a->name)), "=") == 0 &&
+		(exprIsNullConstant(lexpr) || exprIsNullConstant(rexpr)) &&
+		(!IsA(lexpr, CaseTestExpr) && !IsA(rexpr, CaseTestExpr)))
+	{
+		NullTest   *n = makeNode(NullTest);
+
+		n->nulltesttype = IS_NULL;
+		n->location = a->location;
+
+		if (exprIsNullConstant(lexpr))
+			n->arg = (Expr *) rexpr;
+		else
+			n->arg = (Expr *) lexpr;
+
+		result = transformExprRecurse(pstate, (Node *) n);
+	}
+	else if (lexpr && IsA(lexpr, RowExpr) &&
+			 rexpr && IsA(rexpr, SubLink) &&
+			 ((SubLink *) rexpr)->subLinkType == EXPR_SUBLINK)
+	{
+		/*
+		 * Convert "row op subselect" into a ROWCOMPARE sublink. Formerly the
+		 * grammar did this, but now that a row construct is allowed anywhere
+		 * in expressions, it's easier to do it here.
+		 */
+		SubLink    *s = (SubLink *) rexpr;
+
+		s->subLinkType = ROWCOMPARE_SUBLINK;
+		s->testexpr = lexpr;
+		s->operName = a->name;
+		s->location = a->location;
+		result = transformExprRecurse(pstate, (Node *) s);
+	}
+	else if (lexpr && IsA(lexpr, RowExpr) &&
+			 rexpr && IsA(rexpr, RowExpr))
+	{
+		/* ROW() op ROW() is handled specially */
+		lexpr = transformExprRecurse(pstate, lexpr);
+		rexpr = transformExprRecurse(pstate, rexpr);
+
+		result = make_row_comparison_op(pstate,
+										a->name,
+										castNode(RowExpr, lexpr)->args,
+										castNode(RowExpr, rexpr)->args,
+										a->location);
+	}
+	else
+	{
+		/* Ordinary scalar operator */
+		Node	   *last_srf = pstate->p_last_srf;
+
+		lexpr = transformExprRecurse(pstate, lexpr);
+		rexpr = transformExprRecurse(pstate, rexpr);
+
+		result = (Node *) make_op(pstate,
+								  a->name,
+								  lexpr,
+								  rexpr,
+								  last_srf,
+								  a->location);
+	}
+
+	return result;
+}
+
+static Node *
+transformAExprOpAny(ParseState *pstate, A_Expr *a)
+{
+	Node	   *lexpr = transformExprRecurse(pstate, a->lexpr);
+	Node	   *rexpr = transformExprRecurse(pstate, a->rexpr);
+
+	return (Node *) make_scalar_array_op(pstate,
+										 a->name,
+										 true,
+										 lexpr,
+										 rexpr,
+										 a->location);
+}
+
+static Node *
+transformAExprOpAll(ParseState *pstate, A_Expr *a)
+{
+	Node	   *lexpr = transformExprRecurse(pstate, a->lexpr);
+	Node	   *rexpr = transformExprRecurse(pstate, a->rexpr);
+
+	return (Node *) make_scalar_array_op(pstate,
+										 a->name,
+										 false,
+										 lexpr,
+										 rexpr,
+										 a->location);
+}
+
+static Node *
+transformAExprDistinct(ParseState *pstate, A_Expr *a)
+{
+	Node	   *lexpr = a->lexpr;
+	Node	   *rexpr = a->rexpr;
+	Node	   *result;
+
+	/*
+	 * If either input is an undecorated NULL literal, transform to a NullTest
+	 * on the other input. That's simpler to process than a full DistinctExpr,
+	 * and it avoids needing to require that the datatype have an = operator.
+	 */
+	if (exprIsNullConstant(rexpr))
+		return make_nulltest_from_distinct(pstate, a, lexpr);
+	if (exprIsNullConstant(lexpr))
+		return make_nulltest_from_distinct(pstate, a, rexpr);
+
+	lexpr = transformExprRecurse(pstate, lexpr);
+	rexpr = transformExprRecurse(pstate, rexpr);
+
+	if (lexpr && IsA(lexpr, RowExpr) &&
+		rexpr && IsA(rexpr, RowExpr))
+	{
+		/* ROW() op ROW() is handled specially */
+		result = make_row_distinct_op(pstate, a->name,
+									  (RowExpr *) lexpr,
+									  (RowExpr *) rexpr,
+									  a->location);
+	}
+	else
+	{
+		/* Ordinary scalar operator */
+		result = (Node *) make_distinct_op(pstate,
+										   a->name,
+										   lexpr,
+										   rexpr,
+										   a->location);
+	}
+
+	/*
+	 * If it's NOT DISTINCT, we first build a DistinctExpr and then stick a
+	 * NOT on top.
+	 */
+	if (a->kind == AEXPR_NOT_DISTINCT)
+		result = (Node *) makeBoolExpr(NOT_EXPR,
+									   list_make1(result),
+									   a->location);
+
+	return result;
+}
+
+static Node *
+transformAExprNullIf(ParseState *pstate, A_Expr *a)
+{
+	Node	   *lexpr = transformExprRecurse(pstate, a->lexpr);
+	Node	   *rexpr = transformExprRecurse(pstate, a->rexpr);
+	OpExpr	   *result;
+
+	result = (OpExpr *) make_op(pstate,
+								a->name,
+								lexpr,
+								rexpr,
+								pstate->p_last_srf,
+								a->location);
+
+	/*
+	 * The comparison operator itself should yield boolean ...
+	 */
+	if (result->opresulttype != BOOLOID)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("NULLIF requires = operator to yield boolean"),
+				 parser_errposition(pstate, a->location)));
+	if (result->opretset)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+		/* translator: %s is name of a SQL construct, eg NULLIF */
+				 errmsg("%s must not return a set", "NULLIF"),
+				 parser_errposition(pstate, a->location)));
+
+	/*
+	 * ... but the NullIfExpr will yield the first operand's type.
+	 */
+	result->opresulttype = exprType((Node *) linitial(result->args));
+
+	/*
+	 * We rely on NullIfExpr and OpExpr being the same struct
+	 */
+	NodeSetTag(result, T_NullIfExpr);
+
+	return (Node *) result;
+}
+
+static Node *
+transformAExprIn(ParseState *pstate, A_Expr *a)
+{
+	Node	   *result = NULL;
+	Node	   *lexpr;
+	List	   *rexprs;
+	List	   *rvars;
+	List	   *rnonvars;
+	bool		useOr;
+	ListCell   *l;
+
+	/*
+	 * If the operator is <>, combine with AND not OR.
+	 */
+	if (strcmp(strVal(linitial(a->name)), "<>") == 0)
+		useOr = false;
+	else
+		useOr = true;
+
+	/*
+	 * We try to generate a ScalarArrayOpExpr from IN/NOT IN, but this is only
+	 * possible if there is a suitable array type available.  If not, we fall
+	 * back to a boolean condition tree with multiple copies of the lefthand
+	 * expression.  Also, any IN-list items that contain Vars are handled as
+	 * separate boolean conditions, because that gives the planner more scope
+	 * for optimization on such clauses.
+	 *
+	 * First step: transform all the inputs, and detect whether any contain
+	 * Vars.
+	 */
+	lexpr = transformExprRecurse(pstate, a->lexpr);
+	rexprs = rvars = rnonvars = NIL;
+	foreach(l, (List *) a->rexpr)
+	{
+		Node	   *rexpr = transformExprRecurse(pstate, lfirst(l));
+
+		rexprs = lappend(rexprs, rexpr);
+		if (contain_vars_of_level(rexpr, 0))
+			rvars = lappend(rvars, rexpr);
+		else
+			rnonvars = lappend(rnonvars, rexpr);
+	}
+
+	/*
+	 * ScalarArrayOpExpr is only going to be useful if there's more than one
+	 * non-Var righthand item.
+	 */
+	if (list_length(rnonvars) > 1)
+	{
+		List	   *allexprs;
+		Oid			scalar_type;
+		Oid			array_type;
+
+		/*
+		 * Try to select a common type for the array elements.  Note that
+		 * since the LHS' type is first in the list, it will be preferred when
+		 * there is doubt (eg, when all the RHS items are unknown literals).
+		 *
+		 * Note: use list_concat here not lcons, to avoid damaging rnonvars.
+		 */
+		allexprs = list_concat(list_make1(lexpr), rnonvars);
+		scalar_type = select_common_type(pstate, allexprs, NULL, NULL);
+
+		/* We have to verify that the selected type actually works */
+		if (OidIsValid(scalar_type) &&
+			!verify_common_type(scalar_type, allexprs))
+			scalar_type = InvalidOid;
+
+		/*
+		 * Do we have an array type to use?  Aside from the case where there
+		 * isn't one, we don't risk using ScalarArrayOpExpr when the common
+		 * type is RECORD, because the RowExpr comparison logic below can cope
+		 * with some cases of non-identical row types.
+		 */
+		if (OidIsValid(scalar_type) && scalar_type != RECORDOID)
+			array_type = get_array_type(scalar_type);
+		else
+			array_type = InvalidOid;
+		if (array_type != InvalidOid)
+		{
+			/*
+			 * OK: coerce all the right-hand non-Var inputs to the common type
+			 * and build an ArrayExpr for them.
+			 */
+			List	   *aexprs;
+			ArrayExpr  *newa;
+
+			aexprs = NIL;
+			foreach(l, rnonvars)
+			{
+				Node	   *rexpr = (Node *) lfirst(l);
+
+				rexpr = coerce_to_common_type(pstate, rexpr,
+											  scalar_type,
+											  "IN");
+				aexprs = lappend(aexprs, rexpr);
+			}
+			newa = makeNode(ArrayExpr);
+			newa->array_typeid = array_type;
+			/* array_collid will be set by parse_collate.c */
+			newa->element_typeid = scalar_type;
+			newa->elements = aexprs;
+			newa->multidims = false;
+			newa->location = -1;
+
+			result = (Node *) make_scalar_array_op(pstate,
+												   a->name,
+												   useOr,
+												   lexpr,
+												   (Node *) newa,
+												   a->location);
+
+			/* Consider only the Vars (if any) in the loop below */
+			rexprs = rvars;
+		}
+	}
+
+	/*
+	 * Must do it the hard way, ie, with a boolean expression tree.
+	 */
+	foreach(l, rexprs)
+	{
+		Node	   *rexpr = (Node *) lfirst(l);
+		Node	   *cmp;
+
+		if (IsA(lexpr, RowExpr) &&
+			IsA(rexpr, RowExpr))
+		{
+			/* ROW() op ROW() is handled specially */
+			cmp = make_row_comparison_op(pstate,
+										 a->name,
+										 copyObject(((RowExpr *) lexpr)->args),
+										 ((RowExpr *) rexpr)->args,
+										 a->location);
+		}
+		else
+		{
+			/* Ordinary scalar operator */
+			cmp = (Node *) make_op(pstate,
+								   a->name,
+								   copyObject(lexpr),
+								   rexpr,
+								   pstate->p_last_srf,
+								   a->location);
+		}
+
+		cmp = coerce_to_boolean(pstate, cmp, "IN");
+		if (result == NULL)
+			result = cmp;
+		else
+			result = (Node *) makeBoolExpr(useOr ? OR_EXPR : AND_EXPR,
+										   list_make2(result, cmp),
+										   a->location);
+	}
+
+	return result;
+}
+
+static Node *
+transformAExprBetween(ParseState *pstate, A_Expr *a)
+{
+	Node	   *aexpr;
+	Node	   *bexpr;
+	Node	   *cexpr;
+	Node	   *result;
+	Node	   *sub1;
+	Node	   *sub2;
+	List	   *args;
+
+	/* Deconstruct A_Expr into three subexprs */
+	aexpr = a->lexpr;
+	args = castNode(List, a->rexpr);
+	Assert(list_length(args) == 2);
+	bexpr = (Node *) linitial(args);
+	cexpr = (Node *) lsecond(args);
+
+	/*
+	 * Build the equivalent comparison expression.  Make copies of
+	 * multiply-referenced subexpressions for safety.  (XXX this is really
+	 * wrong since it results in multiple runtime evaluations of what may be
+	 * volatile expressions ...)
+	 *
+	 * Ideally we would not use hard-wired operators here but instead use
+	 * opclasses.  However, mixed data types and other issues make this
+	 * difficult:
+	 * http://archives.postgresql.org/pgsql-hackers/2008-08/msg01142.php
+	 */
+	switch (a->kind)
+	{
+		case AEXPR_BETWEEN:
+			args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
+											   aexpr, bexpr,
+											   a->location),
+							  makeSimpleA_Expr(AEXPR_OP, "<=",
+											   copyObject(aexpr), cexpr,
+											   a->location));
+			result = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
+			break;
+		case AEXPR_NOT_BETWEEN:
+			args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
+											   aexpr, bexpr,
+											   a->location),
+							  makeSimpleA_Expr(AEXPR_OP, ">",
+											   copyObject(aexpr), cexpr,
+											   a->location));
+			result = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
+			break;
+		case AEXPR_BETWEEN_SYM:
+			args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
+											   aexpr, bexpr,
+											   a->location),
+							  makeSimpleA_Expr(AEXPR_OP, "<=",
+											   copyObject(aexpr), cexpr,
+											   a->location));
+			sub1 = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
+			args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
+											   copyObject(aexpr), copyObject(cexpr),
+											   a->location),
+							  makeSimpleA_Expr(AEXPR_OP, "<=",
+											   copyObject(aexpr), copyObject(bexpr),
+											   a->location));
+			sub2 = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
+			args = list_make2(sub1, sub2);
+			result = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
+			break;
+		case AEXPR_NOT_BETWEEN_SYM:
+			args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
+											   aexpr, bexpr,
+											   a->location),
+							  makeSimpleA_Expr(AEXPR_OP, ">",
+											   copyObject(aexpr), cexpr,
+											   a->location));
+			sub1 = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
+			args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
+											   copyObject(aexpr), copyObject(cexpr),
+											   a->location),
+							  makeSimpleA_Expr(AEXPR_OP, ">",
+											   copyObject(aexpr), copyObject(bexpr),
+											   a->location));
+			sub2 = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
+			args = list_make2(sub1, sub2);
+			result = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
+			break;
+		default:
+			elog(ERROR, "unrecognized A_Expr kind: %d", a->kind);
+			result = NULL;		/* keep compiler quiet */
+			break;
+	}
+
+	return transformExprRecurse(pstate, result);
+}
+
+static Node *
+transformBoolExpr(ParseState *pstate, BoolExpr *a)
+{
+	List	   *args = NIL;
+	const char *opname;
+	ListCell   *lc;
+
+	switch (a->boolop)
+	{
+		case AND_EXPR:
+			opname = "AND";
+			break;
+		case OR_EXPR:
+			opname = "OR";
+			break;
+		case NOT_EXPR:
+			opname = "NOT";
+			break;
+		default:
+			elog(ERROR, "unrecognized boolop: %d", (int) a->boolop);
+			opname = NULL;		/* keep compiler quiet */
+			break;
+	}
+
+	foreach(lc, a->args)
+	{
+		Node	   *arg = (Node *) lfirst(lc);
+
+		arg = transformExprRecurse(pstate, arg);
+		arg = coerce_to_boolean(pstate, arg, opname);
+		args = lappend(args, arg);
+	}
+
+	return (Node *) makeBoolExpr(a->boolop, args, a->location);
+}
+
+static Node *
+transformFuncCall(ParseState *pstate, FuncCall *fn)
+{
+	Node	   *last_srf = pstate->p_last_srf;
+	List	   *targs;
+	ListCell   *args;
+
+	/* Transform the list of arguments ... */
+	targs = NIL;
+	foreach(args, fn->args)
+	{
+		targs = lappend(targs, transformExprRecurse(pstate,
+													(Node *) lfirst(args)));
+	}
+
+	/*
+	 * When WITHIN GROUP is used, we treat its ORDER BY expressions as
+	 * additional arguments to the function, for purposes of function lookup
+	 * and argument type coercion.  So, transform each such expression and add
+	 * them to the targs list.  We don't explicitly mark where each argument
+	 * came from, but ParseFuncOrColumn can tell what's what by reference to
+	 * list_length(fn->agg_order).
+	 */
+	if (fn->agg_within_group)
+	{
+		Assert(fn->agg_order != NIL);
+		foreach(args, fn->agg_order)
+		{
+			SortBy	   *arg = (SortBy *) lfirst(args);
+
+			targs = lappend(targs, transformExpr(pstate, arg->node,
+												 EXPR_KIND_ORDER_BY));
+		}
+	}
+
+	/* ... and hand off to ParseFuncOrColumn */
+	return ParseFuncOrColumn(pstate,
+							 fn->funcname,
+							 targs,
+							 last_srf,
+							 fn,
+							 false,
+							 fn->location);
+}
+
+static Node *
+transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref)
+{
+	SubLink    *sublink;
+	RowExpr    *rexpr;
+	Query	   *qtree;
+	TargetEntry *tle;
+
+	/* We should only see this in first-stage processing of UPDATE tlists */
+	Assert(pstate->p_expr_kind == EXPR_KIND_UPDATE_SOURCE);
+
+	/* We only need to transform the source if this is the first column */
+	if (maref->colno == 1)
+	{
+		/*
+		 * For now, we only allow EXPR SubLinks and RowExprs as the source of
+		 * an UPDATE multiassignment.  This is sufficient to cover interesting
+		 * cases; at worst, someone would have to write (SELECT * FROM expr)
+		 * to expand a composite-returning expression of another form.
+		 */
+		if (IsA(maref->source, SubLink) &&
+			((SubLink *) maref->source)->subLinkType == EXPR_SUBLINK)
+		{
+			/* Relabel it as a MULTIEXPR_SUBLINK */
+			sublink = (SubLink *) maref->source;
+			sublink->subLinkType = MULTIEXPR_SUBLINK;
+			/* And transform it */
+			sublink = (SubLink *) transformExprRecurse(pstate,
+													   (Node *) sublink);
+
+			qtree = castNode(Query, sublink->subselect);
+
+			/* Check subquery returns required number of columns */
+			if (count_nonjunk_tlist_entries(qtree->targetList) != maref->ncolumns)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("number of columns does not match number of values"),
+						 parser_errposition(pstate, sublink->location)));
+
+			/*
+			 * Build a resjunk tlist item containing the MULTIEXPR SubLink,
+			 * and add it to pstate->p_multiassign_exprs, whence it will later
+			 * get appended to the completed targetlist.  We needn't worry
+			 * about selecting a resno for it; transformUpdateStmt will do
+			 * that.
+			 */
+			tle = makeTargetEntry((Expr *) sublink, 0, NULL, true);
+			pstate->p_multiassign_exprs = lappend(pstate->p_multiassign_exprs,
+												  tle);
+
+			/*
+			 * Assign a unique-within-this-targetlist ID to the MULTIEXPR
+			 * SubLink.  We can just use its position in the
+			 * p_multiassign_exprs list.
+			 */
+			sublink->subLinkId = list_length(pstate->p_multiassign_exprs);
+		}
+		else if (IsA(maref->source, RowExpr))
+		{
+			/* Transform the RowExpr, allowing SetToDefault items */
+			rexpr = (RowExpr *) transformRowExpr(pstate,
+												 (RowExpr *) maref->source,
+												 true);
+
+			/* Check it returns required number of columns */
+			if (list_length(rexpr->args) != maref->ncolumns)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("number of columns does not match number of values"),
+						 parser_errposition(pstate, rexpr->location)));
+
+			/*
+			 * Temporarily append it to p_multiassign_exprs, so we can get it
+			 * back when we come back here for additional columns.
+			 */
+			tle = makeTargetEntry((Expr *) rexpr, 0, NULL, true);
+			pstate->p_multiassign_exprs = lappend(pstate->p_multiassign_exprs,
+												  tle);
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("source for a multiple-column UPDATE item must be a sub-SELECT or ROW() expression"),
+					 parser_errposition(pstate, exprLocation(maref->source))));
+	}
+	else
+	{
+		/*
+		 * Second or later column in a multiassignment.  Re-fetch the
+		 * transformed SubLink or RowExpr, which we assume is still the last
+		 * entry in p_multiassign_exprs.
+		 */
+		Assert(pstate->p_multiassign_exprs != NIL);
+		tle = (TargetEntry *) llast(pstate->p_multiassign_exprs);
+	}
+
+	/*
+	 * Emit the appropriate output expression for the current column
+	 */
+	if (IsA(tle->expr, SubLink))
+	{
+		Param	   *param;
+
+		sublink = (SubLink *) tle->expr;
+		Assert(sublink->subLinkType == MULTIEXPR_SUBLINK);
+		qtree = castNode(Query, sublink->subselect);
+
+		/* Build a Param representing the current subquery output column */
+		tle = (TargetEntry *) list_nth(qtree->targetList, maref->colno - 1);
+		Assert(!tle->resjunk);
+
+		param = makeNode(Param);
+		param->paramkind = PARAM_MULTIEXPR;
+		param->paramid = (sublink->subLinkId << 16) | maref->colno;
+		param->paramtype = exprType((Node *) tle->expr);
+		param->paramtypmod = exprTypmod((Node *) tle->expr);
+		param->paramcollid = exprCollation((Node *) tle->expr);
+		param->location = exprLocation((Node *) tle->expr);
+
+		return (Node *) param;
+	}
+
+	if (IsA(tle->expr, RowExpr))
+	{
+		Node	   *result;
+
+		rexpr = (RowExpr *) tle->expr;
+
+		/* Just extract and return the next element of the RowExpr */
+		result = (Node *) list_nth(rexpr->args, maref->colno - 1);
+
+		/*
+		 * If we're at the last column, delete the RowExpr from
+		 * p_multiassign_exprs; we don't need it anymore, and don't want it in
+		 * the finished UPDATE tlist.  We assume this is still the last entry
+		 * in p_multiassign_exprs.
+		 */
+		if (maref->colno == maref->ncolumns)
+			pstate->p_multiassign_exprs =
+				list_delete_last(pstate->p_multiassign_exprs);
+
+		return result;
+	}
+
+	elog(ERROR, "unexpected expr type in multiassign list");
+	return NULL;				/* keep compiler quiet */
+}
+
+static Node *
+transformCaseExpr(ParseState *pstate, CaseExpr *c)
+{
+	CaseExpr   *newc = makeNode(CaseExpr);
+	Node	   *last_srf = pstate->p_last_srf;
+	Node	   *arg;
+	CaseTestExpr *placeholder;
+	List	   *newargs;
+	List	   *resultexprs;
+	ListCell   *l;
+	Node	   *defresult;
+	Oid			ptype;
+
+	/* transform the test expression, if any */
+	arg = transformExprRecurse(pstate, (Node *) c->arg);
+
+	/* generate placeholder for test expression */
+	if (arg)
+	{
+		/*
+		 * If test expression is an untyped literal, force it to text. We have
+		 * to do something now because we won't be able to do this coercion on
+		 * the placeholder.  This is not as flexible as what was done in 7.4
+		 * and before, but it's good enough to handle the sort of silly coding
+		 * commonly seen.
+		 */
+		if (exprType(arg) == UNKNOWNOID)
+			arg = coerce_to_common_type(pstate, arg, TEXTOID, "CASE");
+
+		/*
+		 * Run collation assignment on the test expression so that we know
+		 * what collation to mark the placeholder with.  In principle we could
+		 * leave it to parse_collate.c to do that later, but propagating the
+		 * result to the CaseTestExpr would be unnecessarily complicated.
+		 */
+		assign_expr_collations(pstate, arg);
+
+		placeholder = makeNode(CaseTestExpr);
+		placeholder->typeId = exprType(arg);
+		placeholder->typeMod = exprTypmod(arg);
+		placeholder->collation = exprCollation(arg);
+	}
+	else
+		placeholder = NULL;
+
+	newc->arg = (Expr *) arg;
+
+	/* transform the list of arguments */
+	newargs = NIL;
+	resultexprs = NIL;
+	foreach(l, c->args)
+	{
+		CaseWhen   *w = lfirst_node(CaseWhen, l);
+		CaseWhen   *neww = makeNode(CaseWhen);
+		Node	   *warg;
+
+		warg = (Node *) w->expr;
+		if (placeholder)
+		{
+			/* shorthand form was specified, so expand... */
+			warg = (Node *) makeSimpleA_Expr(AEXPR_OP, "=",
+											 (Node *) placeholder,
+											 warg,
+											 w->location);
+		}
+		neww->expr = (Expr *) transformExprRecurse(pstate, warg);
+
+		neww->expr = (Expr *) coerce_to_boolean(pstate,
+												(Node *) neww->expr,
+												"CASE/WHEN");
+
+		warg = (Node *) w->result;
+		neww->result = (Expr *) transformExprRecurse(pstate, warg);
+		neww->location = w->location;
+
+		newargs = lappend(newargs, neww);
+		resultexprs = lappend(resultexprs, neww->result);
+	}
+
+	newc->args = newargs;
+
+	/* transform the default clause */
+	defresult = (Node *) c->defresult;
+	if (defresult == NULL)
+	{
+		A_Const    *n = makeNode(A_Const);
+
+		n->val.type = T_Null;
+		n->location = -1;
+		defresult = (Node *) n;
+	}
+	newc->defresult = (Expr *) transformExprRecurse(pstate, defresult);
+
+	/*
+	 * Note: default result is considered the most significant type in
+	 * determining preferred type. This is how the code worked before, but it
+	 * seems a little bogus to me --- tgl
+	 */
+	resultexprs = lcons(newc->defresult, resultexprs);
+
+	ptype = select_common_type(pstate, resultexprs, "CASE", NULL);
+	Assert(OidIsValid(ptype));
+	newc->casetype = ptype;
+	/* casecollid will be set by parse_collate.c */
+
+	/* Convert default result clause, if necessary */
+	newc->defresult = (Expr *)
+		coerce_to_common_type(pstate,
+							  (Node *) newc->defresult,
+							  ptype,
+							  "CASE/ELSE");
+
+	/* Convert when-clause results, if necessary */
+	foreach(l, newc->args)
+	{
+		CaseWhen   *w = (CaseWhen *) lfirst(l);
+
+		w->result = (Expr *)
+			coerce_to_common_type(pstate,
+								  (Node *) w->result,
+								  ptype,
+								  "CASE/WHEN");
+	}
+
+	/* if any subexpression contained a SRF, complain */
+	if (pstate->p_last_srf != last_srf)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+		/* translator: %s is name of a SQL construct, eg GROUP BY */
+				 errmsg("set-returning functions are not allowed in %s",
+						"CASE"),
+				 errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
+				 parser_errposition(pstate,
+									exprLocation(pstate->p_last_srf))));
+
+	newc->location = c->location;
+
+	return (Node *) newc;
+}
+
+static Node *
+transformSubLink(ParseState *pstate, SubLink *sublink)
+{
+	Node	   *result = (Node *) sublink;
+	Query	   *qtree;
+	const char *err;
+
+	/*
+	 * Check to see if the sublink is in an invalid place within the query. We
+	 * allow sublinks everywhere in SELECT/INSERT/UPDATE/DELETE, but generally
+	 * not in utility statements.
+	 */
+	err = NULL;
+	switch (pstate->p_expr_kind)
+	{
+		case EXPR_KIND_NONE:
+			Assert(false);		/* can't happen */
+			break;
+		case EXPR_KIND_OTHER:
+			/* Accept sublink here; caller must throw error if wanted */
+			break;
+		case EXPR_KIND_JOIN_ON:
+		case EXPR_KIND_JOIN_USING:
+		case EXPR_KIND_FROM_SUBSELECT:
+		case EXPR_KIND_FROM_FUNCTION:
+		case EXPR_KIND_WHERE:
+		case EXPR_KIND_POLICY:
+		case EXPR_KIND_HAVING:
+		case EXPR_KIND_FILTER:
+		case EXPR_KIND_WINDOW_PARTITION:
+		case EXPR_KIND_WINDOW_ORDER:
+		case EXPR_KIND_WINDOW_FRAME_RANGE:
+		case EXPR_KIND_WINDOW_FRAME_ROWS:
+		case EXPR_KIND_WINDOW_FRAME_GROUPS:
+		case EXPR_KIND_SELECT_TARGET:
+		case EXPR_KIND_INSERT_TARGET:
+		case EXPR_KIND_UPDATE_SOURCE:
+		case EXPR_KIND_UPDATE_TARGET:
+		case EXPR_KIND_GROUP_BY:
+		case EXPR_KIND_ORDER_BY:
+		case EXPR_KIND_DISTINCT_ON:
+		case EXPR_KIND_LIMIT:
+		case EXPR_KIND_OFFSET:
+		case EXPR_KIND_RETURNING:
+		case EXPR_KIND_VALUES:
+		case EXPR_KIND_VALUES_SINGLE:
+		case EXPR_KIND_CYCLE_MARK:
+			/* okay */
+			break;
+		case EXPR_KIND_CHECK_CONSTRAINT:
+		case EXPR_KIND_DOMAIN_CHECK:
+			err = _("cannot use subquery in check constraint");
+			break;
+		case EXPR_KIND_COLUMN_DEFAULT:
+		case EXPR_KIND_FUNCTION_DEFAULT:
+			err = _("cannot use subquery in DEFAULT expression");
+			break;
+		case EXPR_KIND_INDEX_EXPRESSION:
+			err = _("cannot use subquery in index expression");
+			break;
+		case EXPR_KIND_INDEX_PREDICATE:
+			err = _("cannot use subquery in index predicate");
+			break;
+		case EXPR_KIND_STATS_EXPRESSION:
+			err = _("cannot use subquery in statistics expression");
+			break;
+		case EXPR_KIND_ALTER_COL_TRANSFORM:
+			err = _("cannot use subquery in transform expression");
+			break;
+		case EXPR_KIND_EXECUTE_PARAMETER:
+			err = _("cannot use subquery in EXECUTE parameter");
+			break;
+		case EXPR_KIND_TRIGGER_WHEN:
+			err = _("cannot use subquery in trigger WHEN condition");
+			break;
+		case EXPR_KIND_PARTITION_BOUND:
+			err = _("cannot use subquery in partition bound");
+			break;
+		case EXPR_KIND_PARTITION_EXPRESSION:
+			err = _("cannot use subquery in partition key expression");
+			break;
+		case EXPR_KIND_CALL_ARGUMENT:
+			err = _("cannot use subquery in CALL argument");
+			break;
+		case EXPR_KIND_COPY_WHERE:
+			err = _("cannot use subquery in COPY FROM WHERE condition");
+			break;
+		case EXPR_KIND_GENERATED_COLUMN:
+			err = _("cannot use subquery in column generation expression");
+			break;
+
+			/*
+			 * There is intentionally no default: case here, so that the
+			 * compiler will warn if we add a new ParseExprKind without
+			 * extending this switch.  If we do see an unrecognized value at
+			 * runtime, the behavior will be the same as for EXPR_KIND_OTHER,
+			 * which is sane anyway.
+			 */
+	}
+	if (err)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg_internal("%s", err),
+				 parser_errposition(pstate, sublink->location)));
+
+	pstate->p_hasSubLinks = true;
+
+	/*
+	 * OK, let's transform the sub-SELECT.
+	 */
+	qtree = parse_sub_analyze(sublink->subselect, pstate, NULL, false, true);
+
+	/*
+	 * Check that we got a SELECT.  Anything else should be impossible given
+	 * restrictions of the grammar, but check anyway.
+	 */
+	if (!IsA(qtree, Query) ||
+		qtree->commandType != CMD_SELECT)
+		elog(ERROR, "unexpected non-SELECT command in SubLink");
+
+	sublink->subselect = (Node *) qtree;
+
+	if (sublink->subLinkType == EXISTS_SUBLINK)
+	{
+		/*
+		 * EXISTS needs no test expression or combining operator. These fields
+		 * should be null already, but make sure.
+		 */
+		sublink->testexpr = NULL;
+		sublink->operName = NIL;
+	}
+	else if (sublink->subLinkType == EXPR_SUBLINK ||
+			 sublink->subLinkType == ARRAY_SUBLINK)
+	{
+		/*
+		 * Make sure the subselect delivers a single column (ignoring resjunk
+		 * targets).
+		 */
+		if (count_nonjunk_tlist_entries(qtree->targetList) != 1)
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("subquery must return only one column"),
+					 parser_errposition(pstate, sublink->location)));
+
+		/*
+		 * EXPR and ARRAY need no test expression or combining operator. These
+		 * fields should be null already, but make sure.
+		 */
+		sublink->testexpr = NULL;
+		sublink->operName = NIL;
+	}
+	else if (sublink->subLinkType == MULTIEXPR_SUBLINK)
+	{
+		/* Same as EXPR case, except no restriction on number of columns */
+		sublink->testexpr = NULL;
+		sublink->operName = NIL;
+	}
+	else
+	{
+		/* ALL, ANY, or ROWCOMPARE: generate row-comparing expression */
+		Node	   *lefthand;
+		List	   *left_list;
+		List	   *right_list;
+		ListCell   *l;
+
+		/*
+		 * If the source was "x IN (select)", convert to "x = ANY (select)".
+		 */
+		if (sublink->operName == NIL)
+			sublink->operName = list_make1(makeString("="));
+
+		/*
+		 * Transform lefthand expression, and convert to a list
+		 */
+		lefthand = transformExprRecurse(pstate, sublink->testexpr);
+		if (lefthand && IsA(lefthand, RowExpr))
+			left_list = ((RowExpr *) lefthand)->args;
+		else
+			left_list = list_make1(lefthand);
+
+		/*
+		 * Build a list of PARAM_SUBLINK nodes representing the output columns
+		 * of the subquery.
+		 */
+		right_list = NIL;
+		foreach(l, qtree->targetList)
+		{
+			TargetEntry *tent = (TargetEntry *) lfirst(l);
+			Param	   *param;
+
+			if (tent->resjunk)
+				continue;
+
+			param = makeNode(Param);
+			param->paramkind = PARAM_SUBLINK;
+			param->paramid = tent->resno;
+			param->paramtype = exprType((Node *) tent->expr);
+			param->paramtypmod = exprTypmod((Node *) tent->expr);
+			param->paramcollid = exprCollation((Node *) tent->expr);
+			param->location = -1;
+
+			right_list = lappend(right_list, param);
+		}
+
+		/*
+		 * We could rely on make_row_comparison_op to complain if the list
+		 * lengths differ, but we prefer to generate a more specific error
+		 * message.
+		 */
+		if (list_length(left_list) < list_length(right_list))
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("subquery has too many columns"),
+					 parser_errposition(pstate, sublink->location)));
+		if (list_length(left_list) > list_length(right_list))
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("subquery has too few columns"),
+					 parser_errposition(pstate, sublink->location)));
+
+		/*
+		 * Identify the combining operator(s) and generate a suitable
+		 * row-comparison expression.
+		 */
+		sublink->testexpr = make_row_comparison_op(pstate,
+												   sublink->operName,
+												   left_list,
+												   right_list,
+												   sublink->location);
+	}
+
+	return result;
+}
+
+/*
+ * transformArrayExpr
+ *
+ * If the caller specifies the target type, the resulting array will
+ * be of exactly that type.  Otherwise we try to infer a common type
+ * for the elements using select_common_type().
+ */
+static Node *
+transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
+				   Oid array_type, Oid element_type, int32 typmod)
+{
+	ArrayExpr  *newa = makeNode(ArrayExpr);
+	List	   *newelems = NIL;
+	List	   *newcoercedelems = NIL;
+	ListCell   *element;
+	Oid			coerce_type;
+	bool		coerce_hard;
+
+	/*
+	 * Transform the element expressions
+	 *
+	 * Assume that the array is one-dimensional unless we find an array-type
+	 * element expression.
+	 */
+	newa->multidims = false;
+	foreach(element, a->elements)
+	{
+		Node	   *e = (Node *) lfirst(element);
+		Node	   *newe;
+
+		/*
+		 * If an element is itself an A_ArrayExpr, recurse directly so that we
+		 * can pass down any target type we were given.
+		 */
+		if (IsA(e, A_ArrayExpr))
+		{
+			newe = transformArrayExpr(pstate,
+									  (A_ArrayExpr *) e,
+									  array_type,
+									  element_type,
+									  typmod);
+			/* we certainly have an array here */
+			Assert(array_type == InvalidOid || array_type == exprType(newe));
+			newa->multidims = true;
+		}
+		else
+		{
+			newe = transformExprRecurse(pstate, e);
+
+			/*
+			 * Check for sub-array expressions, if we haven't already found
+			 * one.
+			 */
+			if (!newa->multidims && type_is_array(exprType(newe)))
+				newa->multidims = true;
+		}
+
+		newelems = lappend(newelems, newe);
+	}
+
+	/*
+	 * Select a target type for the elements.
+	 *
+	 * If we haven't been given a target array type, we must try to deduce a
+	 * common type based on the types of the individual elements present.
+	 */
+	if (OidIsValid(array_type))
+	{
+		/* Caller must ensure array_type matches element_type */
+		Assert(OidIsValid(element_type));
+		coerce_type = (newa->multidims ? array_type : element_type);
+		coerce_hard = true;
+	}
+	else
+	{
+		/* Can't handle an empty array without a target type */
+		if (newelems == NIL)
+			ereport(ERROR,
+					(errcode(ERRCODE_INDETERMINATE_DATATYPE),
+					 errmsg("cannot determine type of empty array"),
+					 errhint("Explicitly cast to the desired type, "
+							 "for example ARRAY[]::integer[]."),
+					 parser_errposition(pstate, a->location)));
+
+		/* Select a common type for the elements */
+		coerce_type = select_common_type(pstate, newelems, "ARRAY", NULL);
+
+		if (newa->multidims)
+		{
+			array_type = coerce_type;
+			element_type = get_element_type(array_type);
+			if (!OidIsValid(element_type))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("could not find element type for data type %s",
+								format_type_be(array_type)),
+						 parser_errposition(pstate, a->location)));
+		}
+		else
+		{
+			element_type = coerce_type;
+			array_type = get_array_type(element_type);
+			if (!OidIsValid(array_type))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("could not find array type for data type %s",
+								format_type_be(element_type)),
+						 parser_errposition(pstate, a->location)));
+		}
+		coerce_hard = false;
+	}
+
+	/*
+	 * Coerce elements to target type
+	 *
+	 * If the array has been explicitly cast, then the elements are in turn
+	 * explicitly coerced.
+	 *
+	 * If the array's type was merely derived from the common type of its
+	 * elements, then the elements are implicitly coerced to the common type.
+	 * This is consistent with other uses of select_common_type().
+	 */
+	foreach(element, newelems)
+	{
+		Node	   *e = (Node *) lfirst(element);
+		Node	   *newe;
+
+		if (coerce_hard)
+		{
+			newe = coerce_to_target_type(pstate, e,
+										 exprType(e),
+										 coerce_type,
+										 typmod,
+										 COERCION_EXPLICIT,
+										 COERCE_EXPLICIT_CAST,
+										 -1);
+			if (newe == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_CANNOT_COERCE),
+						 errmsg("cannot cast type %s to %s",
+								format_type_be(exprType(e)),
+								format_type_be(coerce_type)),
+						 parser_errposition(pstate, exprLocation(e))));
+		}
+		else
+			newe = coerce_to_common_type(pstate, e,
+										 coerce_type,
+										 "ARRAY");
+		newcoercedelems = lappend(newcoercedelems, newe);
+	}
+
+	newa->array_typeid = array_type;
+	/* array_collid will be set by parse_collate.c */
+	newa->element_typeid = element_type;
+	newa->elements = newcoercedelems;
+	newa->location = a->location;
+
+	return (Node *) newa;
+}
+
+static Node *
+transformRowExpr(ParseState *pstate, RowExpr *r, bool allowDefault)
+{
+	RowExpr    *newr;
+	char		fname[16];
+	int			fnum;
+
+	newr = makeNode(RowExpr);
+
+	/* Transform the field expressions */
+	newr->args = transformExpressionList(pstate, r->args,
+										 pstate->p_expr_kind, allowDefault);
+
+	/* Disallow more columns than will fit in a tuple */
+	if (list_length(newr->args) > MaxTupleAttributeNumber)
+		ereport(ERROR,
+				(errcode(ERRCODE_TOO_MANY_COLUMNS),
+				 errmsg("ROW expressions can have at most %d entries",
+						MaxTupleAttributeNumber),
+				 parser_errposition(pstate, r->location)));
+
+	/* Barring later casting, we consider the type RECORD */
+	newr->row_typeid = RECORDOID;
+	newr->row_format = COERCE_IMPLICIT_CAST;
+
+	/* ROW() has anonymous columns, so invent some field names */
+	newr->colnames = NIL;
+	for (fnum = 1; fnum <= list_length(newr->args); fnum++)
+	{
+		snprintf(fname, sizeof(fname), "f%d", fnum);
+		newr->colnames = lappend(newr->colnames, makeString(pstrdup(fname)));
+	}
+
+	newr->location = r->location;
+
+	return (Node *) newr;
+}
+
+static Node *
+transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c)
+{
+	CoalesceExpr *newc = makeNode(CoalesceExpr);
+	Node	   *last_srf = pstate->p_last_srf;
+	List	   *newargs = NIL;
+	List	   *newcoercedargs = NIL;
+	ListCell   *args;
+
+	foreach(args, c->args)
+	{
+		Node	   *e = (Node *) lfirst(args);
+		Node	   *newe;
+
+		newe = transformExprRecurse(pstate, e);
+		newargs = lappend(newargs, newe);
+	}
+
+	newc->coalescetype = select_common_type(pstate, newargs, "COALESCE", NULL);
+	/* coalescecollid will be set by parse_collate.c */
+
+	/* Convert arguments if necessary */
+	foreach(args, newargs)
+	{
+		Node	   *e = (Node *) lfirst(args);
+		Node	   *newe;
+
+		newe = coerce_to_common_type(pstate, e,
+									 newc->coalescetype,
+									 "COALESCE");
+		newcoercedargs = lappend(newcoercedargs, newe);
+	}
+
+	/* if any subexpression contained a SRF, complain */
+	if (pstate->p_last_srf != last_srf)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+		/* translator: %s is name of a SQL construct, eg GROUP BY */
+				 errmsg("set-returning functions are not allowed in %s",
+						"COALESCE"),
+				 errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
+				 parser_errposition(pstate,
+									exprLocation(pstate->p_last_srf))));
+
+	newc->args = newcoercedargs;
+	newc->location = c->location;
+	return (Node *) newc;
+}
+
+static Node *
+transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m)
+{
+	MinMaxExpr *newm = makeNode(MinMaxExpr);
+	List	   *newargs = NIL;
+	List	   *newcoercedargs = NIL;
+	const char *funcname = (m->op == IS_GREATEST) ? "GREATEST" : "LEAST";
+	ListCell   *args;
+
+	newm->op = m->op;
+	foreach(args, m->args)
+	{
+		Node	   *e = (Node *) lfirst(args);
+		Node	   *newe;
+
+		newe = transformExprRecurse(pstate, e);
+		newargs = lappend(newargs, newe);
+	}
+
+	newm->minmaxtype = select_common_type(pstate, newargs, funcname, NULL);
+	/* minmaxcollid and inputcollid will be set by parse_collate.c */
+
+	/* Convert arguments if necessary */
+	foreach(args, newargs)
+	{
+		Node	   *e = (Node *) lfirst(args);
+		Node	   *newe;
+
+		newe = coerce_to_common_type(pstate, e,
+									 newm->minmaxtype,
+									 funcname);
+		newcoercedargs = lappend(newcoercedargs, newe);
+	}
+
+	newm->args = newcoercedargs;
+	newm->location = m->location;
+	return (Node *) newm;
+}
+
+static Node *
+transformSQLValueFunction(ParseState *pstate, SQLValueFunction *svf)
+{
+	/*
+	 * All we need to do is insert the correct result type and (where needed)
+	 * validate the typmod, so we just modify the node in-place.
+	 */
+	switch (svf->op)
+	{
+		case SVFOP_CURRENT_DATE:
+			svf->type = DATEOID;
+			break;
+		case SVFOP_CURRENT_TIME:
+			svf->type = TIMETZOID;
+			break;
+		case SVFOP_CURRENT_TIME_N:
+			svf->type = TIMETZOID;
+			svf->typmod = anytime_typmod_check(true, svf->typmod);
+			break;
+		case SVFOP_CURRENT_TIMESTAMP:
+			svf->type = TIMESTAMPTZOID;
+			break;
+		case SVFOP_CURRENT_TIMESTAMP_N:
+			svf->type = TIMESTAMPTZOID;
+			svf->typmod = anytimestamp_typmod_check(true, svf->typmod);
+			break;
+		case SVFOP_LOCALTIME:
+			svf->type = TIMEOID;
+			break;
+		case SVFOP_LOCALTIME_N:
+			svf->type = TIMEOID;
+			svf->typmod = anytime_typmod_check(false, svf->typmod);
+			break;
+		case SVFOP_LOCALTIMESTAMP:
+			svf->type = TIMESTAMPOID;
+			break;
+		case SVFOP_LOCALTIMESTAMP_N:
+			svf->type = TIMESTAMPOID;
+			svf->typmod = anytimestamp_typmod_check(false, svf->typmod);
+			break;
+		case SVFOP_CURRENT_ROLE:
+		case SVFOP_CURRENT_USER:
+		case SVFOP_USER:
+		case SVFOP_SESSION_USER:
+		case SVFOP_CURRENT_CATALOG:
+		case SVFOP_CURRENT_SCHEMA:
+			svf->type = NAMEOID;
+			break;
+	}
+
+	return (Node *) svf;
+}
+
+static Node *
+transformXmlExpr(ParseState *pstate, XmlExpr *x)
+{
+	XmlExpr    *newx;
+	ListCell   *lc;
+	int			i;
+
+	newx = makeNode(XmlExpr);
+	newx->op = x->op;
+	if (x->name)
+		newx->name = map_sql_identifier_to_xml_name(x->name, false, false);
+	else
+		newx->name = NULL;
+	newx->xmloption = x->xmloption;
+	newx->type = XMLOID;		/* this just marks the node as transformed */
+	newx->typmod = -1;
+	newx->location = x->location;
+
+	/*
+	 * gram.y built the named args as a list of ResTarget.  Transform each,
+	 * and break the names out as a separate list.
+	 */
+	newx->named_args = NIL;
+	newx->arg_names = NIL;
+
+	foreach(lc, x->named_args)
+	{
+		ResTarget  *r = lfirst_node(ResTarget, lc);
+		Node	   *expr;
+		char	   *argname;
+
+		expr = transformExprRecurse(pstate, r->val);
+
+		if (r->name)
+			argname = map_sql_identifier_to_xml_name(r->name, false, false);
+		else if (IsA(r->val, ColumnRef))
+			argname = map_sql_identifier_to_xml_name(FigureColname(r->val),
+													 true, false);
+		else
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 x->op == IS_XMLELEMENT
+					 ? errmsg("unnamed XML attribute value must be a column reference")
+					 : errmsg("unnamed XML element value must be a column reference"),
+					 parser_errposition(pstate, r->location)));
+			argname = NULL;		/* keep compiler quiet */
+		}
+
+		/* reject duplicate argnames in XMLELEMENT only */
+		if (x->op == IS_XMLELEMENT)
+		{
+			ListCell   *lc2;
+
+			foreach(lc2, newx->arg_names)
+			{
+				if (strcmp(argname, strVal(lfirst(lc2))) == 0)
+					ereport(ERROR,
+							(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("XML attribute name \"%s\" appears more than once",
+									argname),
+							 parser_errposition(pstate, r->location)));
+			}
+		}
+
+		newx->named_args = lappend(newx->named_args, expr);
+		newx->arg_names = lappend(newx->arg_names, makeString(argname));
+	}
+
+	/* The other arguments are of varying types depending on the function */
+	newx->args = NIL;
+	i = 0;
+	foreach(lc, x->args)
+	{
+		Node	   *e = (Node *) lfirst(lc);
+		Node	   *newe;
+
+		newe = transformExprRecurse(pstate, e);
+		switch (x->op)
+		{
+			case IS_XMLCONCAT:
+				newe = coerce_to_specific_type(pstate, newe, XMLOID,
+											   "XMLCONCAT");
+				break;
+			case IS_XMLELEMENT:
+				/* no coercion necessary */
+				break;
+			case IS_XMLFOREST:
+				newe = coerce_to_specific_type(pstate, newe, XMLOID,
+											   "XMLFOREST");
+				break;
+			case IS_XMLPARSE:
+				if (i == 0)
+					newe = coerce_to_specific_type(pstate, newe, TEXTOID,
+												   "XMLPARSE");
+				else
+					newe = coerce_to_boolean(pstate, newe, "XMLPARSE");
+				break;
+			case IS_XMLPI:
+				newe = coerce_to_specific_type(pstate, newe, TEXTOID,
+											   "XMLPI");
+				break;
+			case IS_XMLROOT:
+				if (i == 0)
+					newe = coerce_to_specific_type(pstate, newe, XMLOID,
+												   "XMLROOT");
+				else if (i == 1)
+					newe = coerce_to_specific_type(pstate, newe, TEXTOID,
+												   "XMLROOT");
+				else
+					newe = coerce_to_specific_type(pstate, newe, INT4OID,
+												   "XMLROOT");
+				break;
+			case IS_XMLSERIALIZE:
+				/* not handled here */
+				Assert(false);
+				break;
+			case IS_DOCUMENT:
+				newe = coerce_to_specific_type(pstate, newe, XMLOID,
+											   "IS DOCUMENT");
+				break;
+		}
+		newx->args = lappend(newx->args, newe);
+		i++;
+	}
+
+	return (Node *) newx;
+}
+
+static Node *
+transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
+{
+	Node	   *result;
+	XmlExpr    *xexpr;
+	Oid			targetType;
+	int32		targetTypmod;
+
+	xexpr = makeNode(XmlExpr);
+	xexpr->op = IS_XMLSERIALIZE;
+	xexpr->args = list_make1(coerce_to_specific_type(pstate,
+													 transformExprRecurse(pstate, xs->expr),
+													 XMLOID,
+													 "XMLSERIALIZE"));
+
+	typenameTypeIdAndMod(pstate, xs->typeName, &targetType, &targetTypmod);
+
+	xexpr->xmloption = xs->xmloption;
+	xexpr->location = xs->location;
+	/* We actually only need these to be able to parse back the expression. */
+	xexpr->type = targetType;
+	xexpr->typmod = targetTypmod;
+
+	/*
+	 * The actual target type is determined this way.  SQL allows char and
+	 * varchar as target types.  We allow anything that can be cast implicitly
+	 * from text.  This way, user-defined text-like data types automatically
+	 * fit in.
+	 */
+	result = coerce_to_target_type(pstate, (Node *) xexpr,
+								   TEXTOID, targetType, targetTypmod,
+								   COERCION_IMPLICIT,
+								   COERCE_IMPLICIT_CAST,
+								   -1);
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast XMLSERIALIZE result to %s",
+						format_type_be(targetType)),
+				 parser_errposition(pstate, xexpr->location)));
+	return result;
+}
+
+static Node *
+transformBooleanTest(ParseState *pstate, BooleanTest *b)
+{
+	const char *clausename;
+
+	switch (b->booltesttype)
+	{
+		case IS_TRUE:
+			clausename = "IS TRUE";
+			break;
+		case IS_NOT_TRUE:
+			clausename = "IS NOT TRUE";
+			break;
+		case IS_FALSE:
+			clausename = "IS FALSE";
+			break;
+		case IS_NOT_FALSE:
+			clausename = "IS NOT FALSE";
+			break;
+		case IS_UNKNOWN:
+			clausename = "IS UNKNOWN";
+			break;
+		case IS_NOT_UNKNOWN:
+			clausename = "IS NOT UNKNOWN";
+			break;
+		default:
+			elog(ERROR, "unrecognized booltesttype: %d",
+				 (int) b->booltesttype);
+			clausename = NULL;	/* keep compiler quiet */
+	}
+
+	b->arg = (Expr *) transformExprRecurse(pstate, (Node *) b->arg);
+
+	b->arg = (Expr *) coerce_to_boolean(pstate,
+										(Node *) b->arg,
+										clausename);
+
+	return (Node *) b;
+}
+
+static Node *
+transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr)
+{
+	/* CURRENT OF can only appear at top level of UPDATE/DELETE */
+	Assert(pstate->p_target_nsitem != NULL);
+	cexpr->cvarno = pstate->p_target_nsitem->p_rtindex;
+
+	/*
+	 * Check to see if the cursor name matches a parameter of type REFCURSOR.
+	 * If so, replace the raw name reference with a parameter reference. (This
+	 * is a hack for the convenience of plpgsql.)
+	 */
+	if (cexpr->cursor_name != NULL) /* in case already transformed */
+	{
+		ColumnRef  *cref = makeNode(ColumnRef);
+		Node	   *node = NULL;
+
+		/* Build an unqualified ColumnRef with the given name */
+		cref->fields = list_make1(makeString(cexpr->cursor_name));
+		cref->location = -1;
+
+		/* See if there is a translation available from a parser hook */
+		if (pstate->p_pre_columnref_hook != NULL)
+			node = pstate->p_pre_columnref_hook(pstate, cref);
+		if (node == NULL && pstate->p_post_columnref_hook != NULL)
+			node = pstate->p_post_columnref_hook(pstate, cref, NULL);
+
+		/*
+		 * XXX Should we throw an error if we get a translation that isn't a
+		 * refcursor Param?  For now it seems best to silently ignore false
+		 * matches.
+		 */
+		if (node != NULL && IsA(node, Param))
+		{
+			Param	   *p = (Param *) node;
+
+			if (p->paramkind == PARAM_EXTERN &&
+				p->paramtype == REFCURSOROID)
+			{
+				/* Matches, so convert CURRENT OF to a param reference */
+				cexpr->cursor_name = NULL;
+				cexpr->cursor_param = p->paramid;
+			}
+		}
+	}
+
+	return (Node *) cexpr;
+}
+
+/*
+ * Construct a whole-row reference to represent the notation "relation.*".
+ */
+static Node *
+transformWholeRowRef(ParseState *pstate, ParseNamespaceItem *nsitem,
+					 int sublevels_up, int location)
+{
+	/*
+	 * Build the appropriate referencing node.  Normally this can be a
+	 * whole-row Var, but if the nsitem is a JOIN USING alias then it contains
+	 * only a subset of the columns of the underlying join RTE, so that will
+	 * not work.  Instead we immediately expand the reference into a RowExpr.
+	 * Since the JOIN USING's common columns are fully determined at this
+	 * point, there seems no harm in expanding it now rather than during
+	 * planning.
+	 *
+	 * Note that if the RTE is a function returning scalar, we create just a
+	 * plain reference to the function value, not a composite containing a
+	 * single column.  This is pretty inconsistent at first sight, but it's
+	 * what we've done historically.  One argument for it is that "rel" and
+	 * "rel.*" mean the same thing for composite relations, so why not for
+	 * scalar functions...
+	 */
+	if (nsitem->p_names == nsitem->p_rte->eref)
+	{
+		Var		   *result;
+
+		result = makeWholeRowVar(nsitem->p_rte, nsitem->p_rtindex,
+								 sublevels_up, true);
+
+		/* location is not filled in by makeWholeRowVar */
+		result->location = location;
+
+		/* mark relation as requiring whole-row SELECT access */
+		markVarForSelectPriv(pstate, result);
+
+		return (Node *) result;
+	}
+	else
+	{
+		RowExpr    *rowexpr;
+		List	   *fields;
+
+		/*
+		 * We want only as many columns as are listed in p_names->colnames,
+		 * and we should use those names not whatever possibly-aliased names
+		 * are in the RTE.  We needn't worry about marking the RTE for SELECT
+		 * access, as the common columns are surely so marked already.
+		 */
+		expandRTE(nsitem->p_rte, nsitem->p_rtindex,
+				  sublevels_up, location, false,
+				  NULL, &fields);
+		rowexpr = makeNode(RowExpr);
+		rowexpr->args = list_truncate(fields,
+									  list_length(nsitem->p_names->colnames));
+		rowexpr->row_typeid = RECORDOID;
+		rowexpr->row_format = COERCE_IMPLICIT_CAST;
+		rowexpr->colnames = copyObject(nsitem->p_names->colnames);
+		rowexpr->location = location;
+
+		return (Node *) rowexpr;
+	}
+}
+
+/*
+ * Handle an explicit CAST construct.
+ *
+ * Transform the argument, look up the type name, and apply any necessary
+ * coercion function(s).
+ */
+static Node *
+transformTypeCast(ParseState *pstate, TypeCast *tc)
+{
+	Node	   *result;
+	Node	   *arg = tc->arg;
+	Node	   *expr;
+	Oid			inputType;
+	Oid			targetType;
+	int32		targetTypmod;
+	int			location;
+
+	/* Look up the type name first */
+	typenameTypeIdAndMod(pstate, tc->typeName, &targetType, &targetTypmod);
+
+	/*
+	 * If the subject of the typecast is an ARRAY[] construct and the target
+	 * type is an array type, we invoke transformArrayExpr() directly so that
+	 * we can pass down the type information.  This avoids some cases where
+	 * transformArrayExpr() might not infer the correct type.  Otherwise, just
+	 * transform the argument normally.
+	 */
+	if (IsA(arg, A_ArrayExpr))
+	{
+		Oid			targetBaseType;
+		int32		targetBaseTypmod;
+		Oid			elementType;
+
+		/*
+		 * If target is a domain over array, work with the base array type
+		 * here.  Below, we'll cast the array type to the domain.  In the
+		 * usual case that the target is not a domain, the remaining steps
+		 * will be a no-op.
+		 */
+		targetBaseTypmod = targetTypmod;
+		targetBaseType = getBaseTypeAndTypmod(targetType, &targetBaseTypmod);
+		elementType = get_element_type(targetBaseType);
+		if (OidIsValid(elementType))
+		{
+			expr = transformArrayExpr(pstate,
+									  (A_ArrayExpr *) arg,
+									  targetBaseType,
+									  elementType,
+									  targetBaseTypmod);
+		}
+		else
+			expr = transformExprRecurse(pstate, arg);
+	}
+	else
+		expr = transformExprRecurse(pstate, arg);
+
+	inputType = exprType(expr);
+	if (inputType == InvalidOid)
+		return expr;			/* do nothing if NULL input */
+
+	/*
+	 * Location of the coercion is preferentially the location of the :: or
+	 * CAST symbol, but if there is none then use the location of the type
+	 * name (this can happen in TypeName 'string' syntax, for instance).
+	 */
+	location = tc->location;
+	if (location < 0)
+		location = tc->typeName->location;
+
+	result = coerce_to_target_type(pstate, expr, inputType,
+								   targetType, targetTypmod,
+								   COERCION_EXPLICIT,
+								   COERCE_EXPLICIT_CAST,
+								   location);
+	if (result == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_CANNOT_COERCE),
+				 errmsg("cannot cast type %s to %s",
+						format_type_be(inputType),
+						format_type_be(targetType)),
+				 parser_coercion_errposition(pstate, location, expr)));
+
+	return result;
+}
+
+/*
+ * Handle an explicit COLLATE clause.
+ *
+ * Transform the argument, and look up the collation name.
+ */
+static Node *
+transformCollateClause(ParseState *pstate, CollateClause *c)
+{
+	CollateExpr *newc;
+	Oid			argtype;
+
+	newc = makeNode(CollateExpr);
+	newc->arg = (Expr *) transformExprRecurse(pstate, c->arg);
+
+	argtype = exprType((Node *) newc->arg);
+
+	/*
+	 * The unknown type is not collatable, but coerce_type() takes care of it
+	 * separately, so we'll let it go here.
+	 */
+	if (!type_is_collatable(argtype) && argtype != UNKNOWNOID)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("collations are not supported by type %s",
+						format_type_be(argtype)),
+				 parser_errposition(pstate, c->location)));
+
+	newc->collOid = LookupCollation(pstate, c->collname, c->location);
+	newc->location = c->location;
+
+	return (Node *) newc;
+}
+
+/*
+ * Transform a "row compare-op row" construct
+ *
+ * The inputs are lists of already-transformed expressions.
+ * As with coerce_type, pstate may be NULL if no special unknown-Param
+ * processing is wanted.
+ *
+ * The output may be a single OpExpr, an AND or OR combination of OpExprs,
+ * or a RowCompareExpr.  In all cases it is guaranteed to return boolean.
+ * The AND, OR, and RowCompareExpr cases further imply things about the
+ * behavior of the operators (ie, they behave as =, <>, or < <= > >=).
+ */
+static Node *
+make_row_comparison_op(ParseState *pstate, List *opname,
+					   List *largs, List *rargs, int location)
+{
+	RowCompareExpr *rcexpr;
+	RowCompareType rctype;
+	List	   *opexprs;
+	List	   *opnos;
+	List	   *opfamilies;
+	ListCell   *l,
+			   *r;
+	List	  **opinfo_lists;
+	Bitmapset  *strats;
+	int			nopers;
+	int			i;
+
+	nopers = list_length(largs);
+	if (nopers != list_length(rargs))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("unequal number of entries in row expressions"),
+				 parser_errposition(pstate, location)));
+
+	/*
+	 * We can't compare zero-length rows because there is no principled basis
+	 * for figuring out what the operator is.
+	 */
+	if (nopers == 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot compare rows of zero length"),
+				 parser_errposition(pstate, location)));
+
+	/*
+	 * Identify all the pairwise operators, using make_op so that behavior is
+	 * the same as in the simple scalar case.
+	 */
+	opexprs = NIL;
+	forboth(l, largs, r, rargs)
+	{
+		Node	   *larg = (Node *) lfirst(l);
+		Node	   *rarg = (Node *) lfirst(r);
+		OpExpr	   *cmp;
+
+		cmp = castNode(OpExpr, make_op(pstate, opname, larg, rarg,
+									   pstate->p_last_srf, location));
+
+		/*
+		 * We don't use coerce_to_boolean here because we insist on the
+		 * operator yielding boolean directly, not via coercion.  If it
+		 * doesn't yield bool it won't be in any index opfamilies...
+		 */
+		if (cmp->opresulttype != BOOLOID)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("row comparison operator must yield type boolean, "
+							"not type %s",
+							format_type_be(cmp->opresulttype)),
+					 parser_errposition(pstate, location)));
+		if (expression_returns_set((Node *) cmp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("row comparison operator must not return a set"),
+					 parser_errposition(pstate, location)));
+		opexprs = lappend(opexprs, cmp);
+	}
+
+	/*
+	 * If rows are length 1, just return the single operator.  In this case we
+	 * don't insist on identifying btree semantics for the operator (but we
+	 * still require it to return boolean).
+	 */
+	if (nopers == 1)
+		return (Node *) linitial(opexprs);
+
+	/*
+	 * Now we must determine which row comparison semantics (= <> < <= > >=)
+	 * apply to this set of operators.  We look for btree opfamilies
+	 * containing the operators, and see which interpretations (strategy
+	 * numbers) exist for each operator.
+	 */
+	opinfo_lists = (List **) palloc(nopers * sizeof(List *));
+	strats = NULL;
+	i = 0;
+	foreach(l, opexprs)
+	{
+		Oid			opno = ((OpExpr *) lfirst(l))->opno;
+		Bitmapset  *this_strats;
+		ListCell   *j;
+
+		opinfo_lists[i] = get_op_btree_interpretation(opno);
+
+		/*
+		 * convert strategy numbers into a Bitmapset to make the intersection
+		 * calculation easy.
+		 */
+		this_strats = NULL;
+		foreach(j, opinfo_lists[i])
+		{
+			OpBtreeInterpretation *opinfo = lfirst(j);
+
+			this_strats = bms_add_member(this_strats, opinfo->strategy);
+		}
+		if (i == 0)
+			strats = this_strats;
+		else
+			strats = bms_int_members(strats, this_strats);
+		i++;
+	}
+
+	/*
+	 * If there are multiple common interpretations, we may use any one of
+	 * them ... this coding arbitrarily picks the lowest btree strategy
+	 * number.
+	 */
+	i = bms_first_member(strats);
+	if (i < 0)
+	{
+		/* No common interpretation, so fail */
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("could not determine interpretation of row comparison operator %s",
+						strVal(llast(opname))),
+				 errhint("Row comparison operators must be associated with btree operator families."),
+				 parser_errposition(pstate, location)));
+	}
+	rctype = (RowCompareType) i;
+
+	/*
+	 * For = and <> cases, we just combine the pairwise operators with AND or
+	 * OR respectively.
+	 */
+	if (rctype == ROWCOMPARE_EQ)
+		return (Node *) makeBoolExpr(AND_EXPR, opexprs, location);
+	if (rctype == ROWCOMPARE_NE)
+		return (Node *) makeBoolExpr(OR_EXPR, opexprs, location);
+
+	/*
+	 * Otherwise we need to choose exactly which opfamily to associate with
+	 * each operator.
+	 */
+	opfamilies = NIL;
+	for (i = 0; i < nopers; i++)
+	{
+		Oid			opfamily = InvalidOid;
+		ListCell   *j;
+
+		foreach(j, opinfo_lists[i])
+		{
+			OpBtreeInterpretation *opinfo = lfirst(j);
+
+			if (opinfo->strategy == rctype)
+			{
+				opfamily = opinfo->opfamily_id;
+				break;
+			}
+		}
+		if (OidIsValid(opfamily))
+			opfamilies = lappend_oid(opfamilies, opfamily);
+		else					/* should not happen */
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("could not determine interpretation of row comparison operator %s",
+							strVal(llast(opname))),
+					 errdetail("There are multiple equally-plausible candidates."),
+					 parser_errposition(pstate, location)));
+	}
+
+	/*
+	 * Now deconstruct the OpExprs and create a RowCompareExpr.
+	 *
+	 * Note: can't just reuse the passed largs/rargs lists, because of
+	 * possibility that make_op inserted coercion operations.
+	 */
+	opnos = NIL;
+	largs = NIL;
+	rargs = NIL;
+	foreach(l, opexprs)
+	{
+		OpExpr	   *cmp = (OpExpr *) lfirst(l);
+
+		opnos = lappend_oid(opnos, cmp->opno);
+		largs = lappend(largs, linitial(cmp->args));
+		rargs = lappend(rargs, lsecond(cmp->args));
+	}
+
+	rcexpr = makeNode(RowCompareExpr);
+	rcexpr->rctype = rctype;
+	rcexpr->opnos = opnos;
+	rcexpr->opfamilies = opfamilies;
+	rcexpr->inputcollids = NIL; /* assign_expr_collations will fix this */
+	rcexpr->largs = largs;
+	rcexpr->rargs = rargs;
+
+	return (Node *) rcexpr;
+}
+
+/*
+ * Transform a "row IS DISTINCT FROM row" construct
+ *
+ * The input RowExprs are already transformed
+ */
+static Node *
+make_row_distinct_op(ParseState *pstate, List *opname,
+					 RowExpr *lrow, RowExpr *rrow,
+					 int location)
+{
+	Node	   *result = NULL;
+	List	   *largs = lrow->args;
+	List	   *rargs = rrow->args;
+	ListCell   *l,
+			   *r;
+
+	if (list_length(largs) != list_length(rargs))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("unequal number of entries in row expressions"),
+				 parser_errposition(pstate, location)));
+
+	forboth(l, largs, r, rargs)
+	{
+		Node	   *larg = (Node *) lfirst(l);
+		Node	   *rarg = (Node *) lfirst(r);
+		Node	   *cmp;
+
+		cmp = (Node *) make_distinct_op(pstate, opname, larg, rarg, location);
+		if (result == NULL)
+			result = cmp;
+		else
+			result = (Node *) makeBoolExpr(OR_EXPR,
+										   list_make2(result, cmp),
+										   location);
+	}
+
+	if (result == NULL)
+	{
+		/* zero-length rows?  Generate constant FALSE */
+		result = makeBoolConst(false, false);
+	}
+
+	return result;
+}
+
+/*
+ * make the node for an IS DISTINCT FROM operator
+ */
+static Expr *
+make_distinct_op(ParseState *pstate, List *opname, Node *ltree, Node *rtree,
+				 int location)
+{
+	Expr	   *result;
+
+	result = make_op(pstate, opname, ltree, rtree,
+					 pstate->p_last_srf, location);
+	if (((OpExpr *) result)->opresulttype != BOOLOID)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("IS DISTINCT FROM requires = operator to yield boolean"),
+				 parser_errposition(pstate, location)));
+	if (((OpExpr *) result)->opretset)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+		/* translator: %s is name of a SQL construct, eg NULLIF */
+				 errmsg("%s must not return a set", "IS DISTINCT FROM"),
+				 parser_errposition(pstate, location)));
+
+	/*
+	 * We rely on DistinctExpr and OpExpr being same struct
+	 */
+	NodeSetTag(result, T_DistinctExpr);
+
+	return result;
+}
+
+/*
+ * Produce a NullTest node from an IS [NOT] DISTINCT FROM NULL construct
+ *
+ * "arg" is the untransformed other argument
+ */
+static Node *
+make_nulltest_from_distinct(ParseState *pstate, A_Expr *distincta, Node *arg)
+{
+	NullTest   *nt = makeNode(NullTest);
+
+	nt->arg = (Expr *) transformExprRecurse(pstate, arg);
+	/* the argument can be any type, so don't coerce it */
+	if (distincta->kind == AEXPR_NOT_DISTINCT)
+		nt->nulltesttype = IS_NULL;
+	else
+		nt->nulltesttype = IS_NOT_NULL;
+	/* argisrow = false is correct whether or not arg is composite */
+	nt->argisrow = false;
+	nt->location = distincta->location;
+	return (Node *) nt;
+}
+
+/*
+ * Produce a string identifying an expression by kind.
+ *
+ * Note: when practical, use a simple SQL keyword for the result.  If that
+ * doesn't work well, check call sites to see whether custom error message
+ * strings are required.
+ */
+const char *
+ParseExprKindName(ParseExprKind exprKind)
+{
+	switch (exprKind)
+	{
+		case EXPR_KIND_NONE:
+			return "invalid expression context";
+		case EXPR_KIND_OTHER:
+			return "extension expression";
+		case EXPR_KIND_JOIN_ON:
+			return "JOIN/ON";
+		case EXPR_KIND_JOIN_USING:
+			return "JOIN/USING";
+		case EXPR_KIND_FROM_SUBSELECT:
+			return "sub-SELECT in FROM";
+		case EXPR_KIND_FROM_FUNCTION:
+			return "function in FROM";
+		case EXPR_KIND_WHERE:
+			return "WHERE";
+		case EXPR_KIND_POLICY:
+			return "POLICY";
+		case EXPR_KIND_HAVING:
+			return "HAVING";
+		case EXPR_KIND_FILTER:
+			return "FILTER";
+		case EXPR_KIND_WINDOW_PARTITION:
+			return "window PARTITION BY";
+		case EXPR_KIND_WINDOW_ORDER:
+			return "window ORDER BY";
+		case EXPR_KIND_WINDOW_FRAME_RANGE:
+			return "window RANGE";
+		case EXPR_KIND_WINDOW_FRAME_ROWS:
+			return "window ROWS";
+		case EXPR_KIND_WINDOW_FRAME_GROUPS:
+			return "window GROUPS";
+		case EXPR_KIND_SELECT_TARGET:
+			return "SELECT";
+		case EXPR_KIND_INSERT_TARGET:
+			return "INSERT";
+		case EXPR_KIND_UPDATE_SOURCE:
+		case EXPR_KIND_UPDATE_TARGET:
+			return "UPDATE";
+		case EXPR_KIND_GROUP_BY:
+			return "GROUP BY";
+		case EXPR_KIND_ORDER_BY:
+			return "ORDER BY";
+		case EXPR_KIND_DISTINCT_ON:
+			return "DISTINCT ON";
+		case EXPR_KIND_LIMIT:
+			return "LIMIT";
+		case EXPR_KIND_OFFSET:
+			return "OFFSET";
+		case EXPR_KIND_RETURNING:
+			return "RETURNING";
+		case EXPR_KIND_VALUES:
+		case EXPR_KIND_VALUES_SINGLE:
+			return "VALUES";
+		case EXPR_KIND_CHECK_CONSTRAINT:
+		case EXPR_KIND_DOMAIN_CHECK:
+			return "CHECK";
+		case EXPR_KIND_COLUMN_DEFAULT:
+		case EXPR_KIND_FUNCTION_DEFAULT:
+			return "DEFAULT";
+		case EXPR_KIND_INDEX_EXPRESSION:
+			return "index expression";
+		case EXPR_KIND_INDEX_PREDICATE:
+			return "index predicate";
+		case EXPR_KIND_STATS_EXPRESSION:
+			return "statistics expression";
+		case EXPR_KIND_ALTER_COL_TRANSFORM:
+			return "USING";
+		case EXPR_KIND_EXECUTE_PARAMETER:
+			return "EXECUTE";
+		case EXPR_KIND_TRIGGER_WHEN:
+			return "WHEN";
+		case EXPR_KIND_PARTITION_BOUND:
+			return "partition bound";
+		case EXPR_KIND_PARTITION_EXPRESSION:
+			return "PARTITION BY";
+		case EXPR_KIND_CALL_ARGUMENT:
+			return "CALL";
+		case EXPR_KIND_COPY_WHERE:
+			return "WHERE";
+		case EXPR_KIND_GENERATED_COLUMN:
+			return "GENERATED AS";
+		case EXPR_KIND_CYCLE_MARK:
+			return "CYCLE";
+
+			/*
+			 * There is intentionally no default: case here, so that the
+			 * compiler will warn if we add a new ParseExprKind without
+			 * extending this switch.  If we do see an unrecognized value at
+			 * runtime, we'll fall through to the "unrecognized" return.
+			 */
+	}
+	return "unrecognized expression kind";
+}