From: Jim C. Nasby <jnasby@pervasive.com>
To: Mark Kirkwood <markir@paradise.net.nz>
Cc: Gregory Stewart <gstewart@sweetdata.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Performance Issues on Opteron Dual Core
Date: Tue, 2 May 2006 15:28:37 -0500
Message-ID: <20060502202837.GC97354@pervasive.com> (raw)
In-Reply-To: <445498AC.10700@paradise.net.nz>
References: <e2tts8$1c70$1@news.hub.org>
<445498AC.10700@paradise.net.nz>
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.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: jnasby@pervasive.com, markir@paradise.net.nz, gstewart@sweetdata.com
Subject: Re: Performance Issues on Opteron Dual Core
In-Reply-To: <20060502202837.GC97354@pervasive.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox