Department of second thoughts: can't reorder merge-join clauses.

tglsfdc · tglsfdc · commit 64a32f9df82e · 2003-08-27T12:44:12.000Z
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.156 2003/08/26 22:56:51 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.157 2003/08/27 12:44:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1000,9 +1000,9 @@ create_mergejoin_plan(Query *root,
 						 best_path->jpath.outerjoinpath->parent->relids);
 
 	/* Sort clauses into best execution order */
+	/* NB: do NOT reorder the mergeclauses */
 	joinclauses = order_qual_clauses(root, joinclauses);
 	otherclauses = order_qual_clauses(root, otherclauses);
-	mergeclauses = order_qual_clauses(root, mergeclauses);
 
 	/*
 	 * Create explicit sort nodes for the outer and inner join paths if

Original file line number	Diff line number	Diff line change
`@@ -10,7 +10,7 @@`
`10`	`10`	`*`
`11`	`11`	`*`
`12`	`12`	`* IDENTIFICATION`
`13`		`- * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.156 2003/08/26 22:56:51 tgl Exp $`
	`13`	`+ * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.157 2003/08/27 12:44:12 tgl Exp $`
`14`	`14`	`*`
`15`	`15`	`*-------------------------------------------------------------------------`
`16`	`16`	`*/`
`@@ -1000,9 +1000,9 @@ create_mergejoin_plan(Query *root,`
`1000`	`1000`	`best_path->jpath.outerjoinpath->parent->relids);`
`1001`	`1001`
`1002`	`1002`	`/* Sort clauses into best execution order */`
	`1003`	`+ /* NB: do NOT reorder the mergeclauses */`
`1003`	`1004`	`joinclauses = order_qual_clauses(root, joinclauses);`
`1004`	`1005`	`otherclauses = order_qual_clauses(root, otherclauses);`
`1005`		`- mergeclauses = order_qual_clauses(root, mergeclauses);`
`1006`	`1006`
`1007`	`1007`	`/*`
`1008`	`1008`	`* Create explicit sort nodes for the outer and inner join paths if`