Re: GEQO status? - Mailing list pgsql-hackers

From Ed Loehr
Subject Re: GEQO status?
Date
Msg-id 3A43E645.B84685E2@austin.rr.com
Whole thread Raw
In response to GEQO status?  (Ed Loehr <eloehr@austin.rr.com>)
List pgsql-hackers
Tom Lane wrote:
> 
> Ed Loehr <eloehr@austin.rr.com> writes:
> > What is the status of the genetic algorithm query optimizer?  Is this
> > supposed to work well on many-table joins, or has it fallen out of favor
> > or in disrepair?
> 
> It's supposed to work ;-).  I'm not sure that the default parameters are
> optimal, however.  If you experiment with other settings, please post your
> results.

Query time dropped from many minutes to 13 seconds on a 12-table join
with a little tweaking from the default params:

My $PGDATA/pg_geqo:
-------------------
Pool_Size            1024
# Effort               high
Generations          100
Random_Seed          330418761
Selection_Bias       2.00

Similar performance with Generations setting of 800 derived from Effort.

Regards,
Ed Loehr


pgsql-hackers by date:

Previous
From: Yusuf Goolamabbas
Date:
Subject: Unable to check out REL7_1 via cvs
Next
From: Alfred Perlstein
Date:
Subject: Re: Unable to check out REL7_1 via cvs