From 48beecda7cbd2e73ebc11c88d3567ad064604bda Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 7 Sep 2003 15:26:54 +0000
Subject: [PATCH] Remove geqo_random_seed parameter. Having geqo reset the
global random() sequence every time it's called is bogus --- it interferes
with user control over the seed, and actually decreases randomness overall
(because a seed based on time(NULL) is pretty predictable). If you really
want a reproducible result from geqo, do 'set seed = 0' before planning a
query.
---
doc/src/sgml/runtime.sgml | 7 ++-----
src/backend/optimizer/geqo/geqo_main.c | 10 +---------
src/backend/utils/misc/guc.c | 11 +----------
src/backend/utils/misc/postgresql.conf.sample | 1 -
src/bin/psql/tab-complete.c | 3 +--
src/include/optimizer/geqo.h | 4 +---
6 files changed, 6 insertions(+), 30 deletions(-)
diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 9bbecfa76bb..425036d81d3 100644
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1,5 +1,5 @@
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.203 2003/09/05 16:13:38 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.204 2003/09/07 15:26:45 tgl Exp $
-->
<Chapter Id="runtime">
@@ -1438,7 +1438,6 @@ SET ENABLE_SEQSCAN TO OFF;
<term><varname>GEQO_EFFORT</varname> (<type>integer</type>)</term>
<term><varname>GEQO_GENERATIONS</varname> (<type>integer</type>)</term>
<term><varname>GEQO_POOL_SIZE</varname> (<type>integer</type>)</term>
- <term><varname>GEQO_RANDOM_SEED</varname> (<type>integer</type>)</term>
<term><varname>GEQO_SELECTION_BIAS</varname> (<type>floating point</type>)</term>
<listitem>
<para>
@@ -1455,9 +1454,7 @@ SET ENABLE_SEQSCAN TO OFF;
is roughly proportional to the sum of pool size and generations.
The selection bias is the selective pressure within the
population. Values can be from 1.50 to 2.00; the latter is the
- default. The random seed can be set to get reproducible results
- from the algorithm. If it is set to -1 then the algorithm
- behaves non-deterministically.
+ default.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/optimizer/geqo/geqo_main.c b/src/backend/optimizer/geqo/geqo_main.c
index d657fdf8db6..031cd665d4f 100644
--- a/src/backend/optimizer/geqo/geqo_main.c
+++ b/src/backend/optimizer/geqo/geqo_main.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Header: /cvsroot/pgsql/src/backend/optimizer/geqo/geqo_main.c,v 1.39 2003/08/12 18:23:20 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/geqo/geqo_main.c,v 1.40 2003/09/07 15:26:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -41,7 +41,6 @@ int Geqo_pool_size;
int Geqo_effort;
int Geqo_generations;
double Geqo_selection_bias;
-int Geqo_random_seed;
static int gimme_pool_size(int nr_rel);
@@ -96,13 +95,6 @@ geqo(Query *root, int number_of_rels, List *initial_rels)
number_generations = gimme_number_generations(pool_size, Geqo_effort);
status_interval = 10;
-/* seed random number generator */
-/* XXX why is this done every time around? */
- if (Geqo_random_seed >= 0)
- srandom((unsigned int) Geqo_random_seed);
- else
- srandom((unsigned int) time(NULL));
-
/* allocate genetic pool memory */
pool = alloc_pool(pool_size, number_of_rels);
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 2129042ed25..709f3090d1a 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
* Written by Peter Eisentraut <peter_e@gmx.net>.
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.155 2003/09/04 05:11:20 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v 1.156 2003/09/07 15:26:53 tgl Exp $
*
*--------------------------------------------------------------------
*/
@@ -898,15 +898,6 @@ static struct config_int ConfigureNamesInt[] =
&Geqo_generations,
0, 0, INT_MAX, NULL, NULL
},
- {
- {"geqo_random_seed", PGC_USERSET, QUERY_TUNING_GEQO,
- gettext_noop("Can be set to get reproducible results from the algorithm"),
- gettext_noop("If it is set to -1 then the algorithm behaves "
- "non-deterministically")
- },
- &Geqo_random_seed,
- -1, INT_MIN, INT_MAX, NULL, NULL
- },
{
{"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index a30ae074a18..c04aaab39bb 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -121,7 +121,6 @@
#geqo_generations = 0
#geqo_pool_size = 0 # default based on tables in statement,
# range 128-1024
-#geqo_random_seed = -1 # -1 = use variable seed
#geqo_selection_bias = 2.0 # range 1.5-2.0
# - Other Planner Options -
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index bcc52be98b7..f6174a73f2d 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -3,7 +3,7 @@
*
* Copyright (c) 2000-2003, PostgreSQL Global Development Group
*
- * $Header: /cvsroot/pgsql/src/bin/psql/tab-complete.c,v 1.84 2003/08/04 23:59:40 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/bin/psql/tab-complete.c,v 1.85 2003/09/07 15:26:54 tgl Exp $
*/
/*----------------------------------------------------------------------
@@ -534,7 +534,6 @@ psql_completion(char *text, int start, int end)
"geqo_effort",
"geqo_generations",
"geqo_pool_size",
- "geqo_random_seed",
"geqo_selection_bias",
"geqo_threshold",
"join_collapse_limit",
diff --git a/src/include/optimizer/geqo.h b/src/include/optimizer/geqo.h
index 0ead9dc304f..53a2334a171 100644
--- a/src/include/optimizer/geqo.h
+++ b/src/include/optimizer/geqo.h
@@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: geqo.h,v 1.31 2003/08/04 02:40:13 momjian Exp $
+ * $Id: geqo.h,v 1.32 2003/09/07 15:26:54 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -64,8 +64,6 @@ extern double Geqo_selection_bias;
#define MIN_GEQO_SELECTION_BIAS 1.5
#define MAX_GEQO_SELECTION_BIAS 2.0
-extern int Geqo_random_seed; /* or negative to use current time */
-
/* routines in geqo_main.c */
extern RelOptInfo *geqo(Query *root, int number_of_rels, List *initial_rels);
--
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