From fa92d21a486de868b21bbc03944649af3e1ac90f Mon Sep 17 00:00:00 2001
From: Tom Lane
Date: Sun, 15 Apr 2007 20:09:28 +0000
Subject: Avoid running build_index_pathkeys() in situations where there cannot
 possibly be any useful pathkeys --- to wit, queries with neither any join
 clauses nor any ORDER BY request.  It's nearly free to check for this case
 and it saves a useful fraction of the planning time for simple queries.

---
 src/include/optimizer/paths.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'src/include/optimizer')

diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h
index 6b985e24cd7..c7b8d8c7521 100644
--- a/src/include/optimizer/paths.h
+++ b/src/include/optimizer/paths.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.96 2007/02/16 00:14:01 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.97 2007/04/15 20:09:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -176,5 +176,6 @@ extern int	pathkeys_useful_for_ordering(PlannerInfo *root, List *pathkeys);
 extern List *truncate_useless_pathkeys(PlannerInfo *root,
 						  RelOptInfo *rel,
 						  List *pathkeys);
+extern bool has_useful_pathkeys(PlannerInfo *root, RelOptInfo *rel);
 
 #endif   /* PATHS_H */
-- 
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