From e4de635a2ba10dcc6fdb972f87fb25953d8d3001 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 5 Jun 2006 03:03:42 +0000
Subject: [PATCH] Increase the default value of cpu_index_tuple_cost from 0.001
to 0.005. This shouldn't affect simple indexscans much, while for bitmap
scans that are touching a lot of index rows, this seems to bring the
estimates more in line with reality. Per recent discussion.
---
doc/src/sgml/config.sgml | 4 ++--
src/backend/utils/misc/postgresql.conf.sample | 2 +-
src/include/optimizer/cost.h | 4 ++--
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 03b47355f38..2226bf40f56 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.60 2006/06/05 02:49:58 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.61 2006/06/05 03:03:42 tgl Exp $ -->
<chapter Id="runtime-config">
<title>Server Configuration</title>
@@ -1831,7 +1831,7 @@ archive_command = 'copy "%p" /mnt/server/archivedir/"%f"' # Windows
<para>
Sets the planner's estimate of the cost of processing
each index entry during an index scan.
- The default is 0.001.
+ The default is 0.005.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 0499223d110..ee5adaa2ff2 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -178,7 +178,7 @@
#seq_page_cost = 1.0 # measured on an arbitrary scale
#random_page_cost = 4.0 # same scale as above
#cpu_tuple_cost = 0.01 # same scale as above
-#cpu_index_tuple_cost = 0.001 # same scale as above
+#cpu_index_tuple_cost = 0.005 # same scale as above
#cpu_operator_cost = 0.0025 # same scale as above
#effective_cache_size = 1000 # typically 8KB each
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index 5d9a6c821c7..ae3f0171fab 100644
--- a/src/include/optimizer/cost.h
+++ b/src/include/optimizer/cost.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/optimizer/cost.h,v 1.74 2006/06/05 02:49:58 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/cost.h,v 1.75 2006/06/05 03:03:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -24,7 +24,7 @@
#define DEFAULT_SEQ_PAGE_COST 1.0
#define DEFAULT_RANDOM_PAGE_COST 4.0
#define DEFAULT_CPU_TUPLE_COST 0.01
-#define DEFAULT_CPU_INDEX_TUPLE_COST 0.001
+#define DEFAULT_CPU_INDEX_TUPLE_COST 0.005
#define DEFAULT_CPU_OPERATOR_COST 0.0025
#define DEFAULT_EFFECTIVE_CACHE_SIZE 1000.0 /* measured in pages */
--
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