From 535756649f8989b460ca1b32803649cdcc6e5c63 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Wed, 11 Jun 2003 15:02:25 +0000
Subject: [PATCH] During looking stuff up for a discussion on -general, I
 realized that I'd placed the check for newly created matching pk rows for on
 update no action earlier than it needed to be so that it'd check even when
 the key values hadn't changed.  This patch moves it to after checking for
 NULLs in the old row and comparing the values since the select's probably
 more expensive.

Stephan Szabo
---
 src/backend/utils/adt/ri_triggers.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index 7f45d347d3..b940315bbf 100644
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -17,7 +17,7 @@
  *
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.50 2003/04/26 22:21:47 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.51 2003/06/11 15:02:25 momjian Exp $
  *
  * ----------
  */
@@ -883,17 +883,6 @@ RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
 	old_row = trigdata->tg_trigtuple;
 
 	match_type = ri_DetermineMatchType(tgargs[RI_MATCH_TYPE_ARGNO]);
-	if (ri_Check_Pk_Match(pk_rel, fk_rel,
-						  old_row, trigdata->tg_trigger->tgoid,
-						  match_type, tgnargs, tgargs))
-	{
-		/*
-		 * There's either another row, or no row could match this one.  In
-		 * either case, we don't need to do the check.
-		 */
-		heap_close(fk_rel, RowShareLock);
-		return PointerGetDatum(NULL);
-	}
 
 	switch (match_type)
 	{
@@ -941,6 +930,18 @@ RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
 				return PointerGetDatum(NULL);
 			}
 
+			if (ri_Check_Pk_Match(pk_rel, fk_rel,
+								  old_row, trigdata->tg_trigger->tgoid,
+								  match_type, tgnargs, tgargs))
+			{
+				/*
+				 * There's either another row, or no row could match this one.  In
+				 * either case, we don't need to do the check.
+				 */
+				heap_close(fk_rel, RowShareLock);
+				return PointerGetDatum(NULL);
+			}
+
 			if (SPI_connect() != SPI_OK_CONNECT)
 				elog(ERROR, "SPI_connect() failed in RI_FKey_noaction_upd()");