Re: Huge performance problem between 7.4.1 and 8.0.3 - CS

From: Robert Creager <Robert_Creager(at)LogicalChaos(dot)org>
To: Robert Creager <Robert_Creager(at)StorageTek(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Robert Creager <Robert_Creager(at)StorageTek(dot)com>, pgsql-performance(at)postgresql(dot)org, Andy Hewitt III <ralph_hewitt_iii(at)StorageTek(dot)com>
Subject: Re: Huge performance problem between 7.4.1 and 8.0.3 - CS
Date: 2005-07-20 04:49:08
Message-ID: 20050719224908.15415222@thunder.logicalchaos.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

When grilled further on (Tue, 19 Jul 2005 12:09:51 -0600),
Robert Creager <Robert_Creager(at)StorageTek(dot)com> confessed:

> On Tue, 19 Jul 2005 12:54:22 -0400
> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> > Hmm, I hadn't thought about the possible impact of multiple concurrent
> > vacuums. Is the problem caused by that, or has performance already gone
> > into the tank by the time the cron-driven vacuums are taking long enough
> > to overlap?
>
>
> I'll re-start the database, vacuum full analyze and restart the runs without
the
> cron vacuum running.
>

It took a few hours, but the problem did finally occur with no vacuum running on
803. CS is averaging 72k. I cannot quantitatively say it took longer to
reproduce than with the vacuums running, but it seemed like it did.

Can any information be gotten out of this? Should I try CVS HEAD?

Thoughts?

Thanks,
Rob

--
22:41:36 up 6 days, 2:16, 6 users, load average: 0.15, 0.21, 0.30
Linux 2.6.5-02 #8 SMP Mon Jul 12 21:34:44 MDT 2004

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Marc Mamin 2005-07-20 09:05:17 Re: Looking for tips
Previous Message Oliver Crosby 2005-07-20 01:50:18 Re: Looking for tips