Re: [SQL] 6.4.x vs. 6.5 oddity

Bruce Momjian <maillist@candle.pha.pa.us>

From: Bruce Momjian <maillist@candle.pha.pa.us>
To: pierre@desertmoon.com
Cc: pgsql-sql@postgreSQL.org
Date: 1999-03-08T20:22:42Z
Lists: pgsql-sql
> > 
> > > All,
> > >   I have started playing with 6.5 and duped my DB onto a
> > > spare box. I grabbed one of the most intensive queries that
> > > runs under the current system and ran it on 6.5. It took
> > > FOREVER. I then ran explain on both 6.4 and 6.5 and here is
> > > the output for both...can anyone explain what the issue is here?
> > > Or is it just that 6.5 is still in development?
> > > 
> > > (All tables are vacuumed)
> > > 
> > 
> > Also, during the recent weeks, GEQO was being enabled for >= 6 tables. 
> > Try SET GEQO TO 'off'.  The current CVS has the GEQO setting at 11.
> > 
> 
> Ahh..tat fixed it. I already had the db vacuum analyze(d) and setting
> GEQO to off gave me an EXPLAIN that was close to the one from 6.4
> here it is:

Good.

> 
> I do have one question...this particular query is taking about 20 seconds
> to return...I've got postmaster setup with -i -B 512 -S -o -F, I had read
> on this list that 6.5 was supposed to have a bit of a speed increase. Of
> course this could be that I've only got 32MB in this test machine..?

Should be much faster for joining many tables like this case.

-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026