From: Joshua D. Drake <jd@commandprompt.com>
To: Christiaan Willemsen <cwillemsen@technocon.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Configuring for maximum memory usage
Date: Thu, 30 Oct 2008 08:45:12 -0700
Message-ID: <4909D688.1090806@commandprompt.com> (raw)
In-Reply-To: <4909CF9C.80701@technocon.com>
References: <4909CF9C.80701@technocon.com>
Christiaan Willemsen wrote:
> Hi there,
> The problem is getting it to use that much. At the moment, it only uses
> almost 9 GB, so by far not enough. The problem is getting it to use
> more... I hope you can help me with working config.
PostgreSQL is only going to use what it needs. It relies on the OS for
much of the caching etc...
>
> Here are the parameters I set in the config file:
>
> shared_buffers = 8192MB
I wouldn't take this any higher.
> work_mem = 128MB
This is quite high but it might be o.k. depending on what you are doing.
> maintenance_work_mem = 2048MB
This is only used during maintenance so you won't see this much.
> max_fsm_pages = 204800
> max_fsm_relations = 2000
This uses very little memory.
>
> Database is about 250 GB in size, so we really need to have as much data
> as possible in memory.
>
> I hope you can help us tweak a few parameters to make sure all memory
> will be used.
You are missing effective_cache_size. Try setting that to 32G.
You also didn't mention checkpoint_segments (which isn't memory but
still important) and default_statistics_target (which isn't memory but
still important).
Joshua D. Drake
>
>
>
>
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: jd@commandprompt.com, cwillemsen@technocon.com
Subject: Re: Configuring for maximum memory usage
In-Reply-To: <4909D688.1090806@commandprompt.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