From a66e2c88855a8c290149d03cfcd6c6a2a5dc53fe Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 26 Nov 2005 18:07:40 +0000
Subject: [PATCH] Teach push_nots() how to negate a ScalarArrayOpExpr.  In
 passing, save a palloc or two in the OpExpr case.

---
 src/backend/optimizer/prep/prepqual.c | 41 +++++++++++++++++++++++----
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/src/backend/optimizer/prep/prepqual.c b/src/backend/optimizer/prep/prepqual.c
index 106d4d1681..520e35f4d1 100644
--- a/src/backend/optimizer/prep/prepqual.c
+++ b/src/backend/optimizer/prep/prepqual.c
@@ -25,7 +25,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepqual.c,v 1.52 2005/11/22 18:17:14 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepqual.c,v 1.53 2005/11/26 18:07:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -212,11 +212,40 @@ push_nots(Expr *qual)
 		Oid			negator = get_negator(opexpr->opno);
 
 		if (negator)
-			return make_opclause(negator,
-								 opexpr->opresulttype,
-								 opexpr->opretset,
-								 (Expr *) get_leftop(qual),
-								 (Expr *) get_rightop(qual));
+		{
+			OpExpr *newopexpr = makeNode(OpExpr);
+
+			newopexpr->opno = negator;
+			newopexpr->opfuncid = InvalidOid;
+			newopexpr->opresulttype = opexpr->opresulttype;
+			newopexpr->opretset = opexpr->opretset;
+			newopexpr->args = opexpr->args;
+			return (Expr *) newopexpr;
+		}
+		else
+			return make_notclause(qual);
+	}
+	else if (qual && IsA(qual, ScalarArrayOpExpr))
+	{
+		/*
+		 * Negate a ScalarArrayOpExpr if there is a negator for its operator;
+		 * for example x = ANY (list) becomes x <> ALL (list).
+		 * Otherwise, retain the clause as it is (the NOT can't be pushed down
+		 * any farther).
+		 */
+		ScalarArrayOpExpr *saopexpr = (ScalarArrayOpExpr *) qual;
+		Oid			negator = get_negator(saopexpr->opno);
+
+		if (negator)
+		{
+			ScalarArrayOpExpr *newopexpr = makeNode(ScalarArrayOpExpr);
+
+			newopexpr->opno = negator;
+			newopexpr->opfuncid = InvalidOid;
+			newopexpr->useOr = !saopexpr->useOr;
+			newopexpr->args = saopexpr->args;
+			return (Expr *) newopexpr;
+		}
 		else
 			return make_notclause(qual);
 	}