pgsql-server/ oc/src/sgml/runtime.sgml rc/back ...

Started by Tom Laneover 22 years ago3 messagescomitters
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#1Tom Lane
tgl@sss.pgh.pa.us

CVSROOT: /cvsroot
Module name: pgsql-server
Changes by: tgl@svr1.postgresql.org 04/01/21 19:33:34

Modified files:
doc/src/sgml : runtime.sgml
src/backend/optimizer/geqo: geqo_main.c
src/backend/utils/misc: guc.c postgresql.conf.sample
src/include/optimizer: geqo.h

Log message:
Repair error apparently introduced in the initial coding of GUC: the
default value for geqo_effort is supposed to be 40, not 1. The actual
'genetic' component of the GEQO algorithm has been practically disabled
since 7.1 because of this mistake. Improve documentation while at it.

#2Neil Conway
neilc@samurai.com
In reply to: Tom Lane (#1)
Re: pgsql-server/ oc/src/sgml/runtime.sgml rc/back ...

tgl@svr1.postgresql.org (Tom Lane) writes:

Repair error apparently introduced in the initial coding of GUC: the
default value for geqo_effort is supposed to be 40, not 1. The actual
'genetic' component of the GEQO algorithm has been practically disabled
since 7.1 because of this mistake.

Is this worth considering for a backport to the 7.4 branch?

-Neil

#3Tom Lane
tgl@sss.pgh.pa.us
In reply to: Neil Conway (#2)
Re: pgsql-server/ oc/src/sgml/runtime.sgml rc/back ...

Neil Conway <neilc@samurai.com> writes:

tgl@svr1.postgresql.org (Tom Lane) writes:

Repair error apparently introduced in the initial coding of GUC: the
default value for geqo_effort is supposed to be 40, not 1. The actual
'genetic' component of the GEQO algorithm has been practically disabled
since 7.1 because of this mistake.

Is this worth considering for a backport to the 7.4 branch?

Considering it's been broken for several releases and no one noticed,
I'm not sure it's critical. This is just something I noticed while
looking at Mike's recent complaint that GEQO is too slow. This change
actually makes it slower :-( but I'm hoping to find that we can buy
that back with other improvements.

regards, tom lane