From: Josh Berkus <josh@agliodbs.com>
To: pgsql-performance@postgresql.org
Cc: John Parnefjord <John.Parnefjord@kib.ki.se>
Subject: Re: Tuning
Date: Sun, 28 Jan 2007 15:24:24 -0800
Message-ID: <200701281524.24317.josh@agliodbs.com> (raw)
In-Reply-To: <76C73999206F3145A2E3046A5C32A103F02A5A@kibmail.kib.local>
References: <76C73999206F3145A2E3046A5C32A103F02A5A@kibmail.kib.local>
John,
> -work_mem
Depends on the number of concurrent queries you expect to run and what size
sorts you expect them to do.
> -maintenance_work_mem - 50% of the largest table?
Actually, in current code I've found that anything over 256mb doesn't actually
get used.
> -shared_buffers - max value 50000
Actually, I need to update that. On newer faster multi-core machines you may
want to allocate up to 1GB of shared buffers.
> -effective_cache_size - max 2/3 of available ram, ie 24GB on the
> hardware described above
Yes.
> -shmmax - how large dare I set this value on dedicated postgres servers?
Set it to 2GB and you'll be covered.
> -checkpoint_segments - this is crucial as one of the server is
> transaction heavy
Well, it only helps you to raise this if you have a dedicated disk resource
for the xlog. Otherwise having more segments doesn't help you much.
> -vacuum_cost_delay
Try 200ms to start.
Also, set wal_buffers to 128.
--
Josh Berkus
PostgreSQL @ Sun
San Francisco
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: josh@agliodbs.com, John.Parnefjord@kib.ki.se
Subject: Re: Tuning
In-Reply-To: <200701281524.24317.josh@agliodbs.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