From: Greg Smith <gsmith@gregsmith.com>
To: John Huttley <John@mib-infotech.co.nz>
Cc: pgsql-performance@postgresql.org
Subject: Re: Slow updates, poor IO
Date: Sat, 27 Sep 2008 03:04:08 -0400 (EDT)
Message-ID: <Pine.GSO.4.64.0809270301290.27800@westnet.com> (raw)
In-Reply-To: <48DD6BAB.8040302@mib-infotech.co.nz>
References: <48DBE587.3050406@mib-infotech.co.nz>
<Pine.GSO.4.64.0809251750130.16879@westnet.com>
<48DD6BAB.8040302@mib-infotech.co.nz>
On Sat, 27 Sep 2008, John Huttley wrote:
> I've got 32M shared on a 1G machine and 16 checkpoint segments.
> I'll run some tests against 64 segments and see what happens.
Increase shared_buffers to 256MB as well. That combination should give
you much better performance with the type of update you're doing. Right
now the database server has to write the index blocks updated to disk all
the time because it has so little working room to store them in. If an
index block is updated but there is room to keep it memory, it doesn't
have to get written out, which considerably lowers the overhead here.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
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: gsmith@gregsmith.com, John@mib-infotech.co.nz
Subject: Re: Slow updates, poor IO
In-Reply-To: <Pine.GSO.4.64.0809270301290.27800@westnet.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