From: Markus Schaber <schabi@logix-tt.com>
To: Tim Allen <tim@proximity.com.au>
Cc: pgsql-performance@postgresql.org
Subject: Re: SAN performance mystery
Date: Fri, 23 Jun 2006 13:56:16 +0200
Message-ID: <449BD6E0.10305@logix-tt.com> (raw)
In-Reply-To: <4491D61B.9040507@proximity.com.au>
References: <4491D61B.9040507@proximity.com.au>
Hi, Tim,
Tim Allen wrote:
> One thing that has been
> apparent is that autovacuum has not been able to keep the database
> sufficiently tamed. A pg_dump/pg_restore cycle reduced the total
> database size from 81G to 36G.
Two first shots:
- Increase your free_space_map settings, until (auto)vacuum does not
warn about a too small FSM setting any more
- Tune autovacuum to run more often, possibly with a higher delay
setting to lower the load.
If you still have the original database around,
> Performing the restore took about 23 hours.
Try to put the WAL on another spindle, and increase the WAL size /
checkpoint segments.
When most of the restore time was spent in index creation, increase the
sort mem / maintainance work mem settings.
HTH,
Markus
--
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf. | Software Development GIS
Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org
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: schabi@logix-tt.com, tim@proximity.com.au
Subject: Re: SAN performance mystery
In-Reply-To: <449BD6E0.10305@logix-tt.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