diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2003-09-07 15:26:54 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2003-09-07 15:26:54 +0000 |
| commit | 48beecda7cbd2e73ebc11c88d3567ad064604bda (patch) | |
| tree | bbe6fd0b76dc6ac7f18cefa3bb86ce19eec5c8b5 /doc/src | |
| parent | 75c35e0f313d58fbbc65169dec13ce19e9886c99 (diff) | |
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.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/runtime.sgml | 7 |
1 files changed, 2 insertions, 5 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> |