Re: Performance Issues on Opteron Dual Core

From: "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com>
To: Jan de Visser <jdevisser(at)digitalfairway(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Performance Issues on Opteron Dual Core
Date: 2006-05-02 22:56:28
Message-ID: 20060502225628.GM97354@pervasive.com
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On Tue, May 02, 2006 at 06:49:48PM -0400, Jan de Visser wrote:
> On Tuesday 02 May 2006 16:28, Jim C. Nasby wrote:
> > On Sun, Apr 30, 2006 at 10:59:56PM +1200, Mark Kirkwood wrote:
> > > Pgadmin can give misleading times for queries that return large result
> > > sets over a network, due to:
> > >
> > > 1/ It takes time to format the (large) result set for display.
> > > 2/ It has to count the time spent waiting for the (large) result set to
> > > travel across the network.
> > >
> > > You aren't running Pgadmin off the dev server are you? If not check your
> > > network link to dev and prod - is one faster than the other? (etc).
> > >
> > > To eliminate Pgadmin and the network as factors try wrapping your query
> > > in a 'SELECT count(*) FROM (your query here) AS a', and see if it
> > > changes anything!
> >
> > FWIW, I've found problems running PostgreSQL on Windows in a multi-CPU
> > environment on w2k3. It runs fine for some period, and then CPU and
> > throughput drop to zero. So far I've been unable to track down any more
> > information than that, other than the fact that I haven't been able to
> > reproduce this on any single-CPU machines.
>
> I have had previous correspondence about this with Magnus (search -general
> and -hackers). If you uninstall SP1 the problem goes away. We played a bit
> with potential fixes but didn't find any.

Interesting; does SP2 fix the problem? Anything we can do over here to
help?
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461

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