From: Scott Marlowe <scott.marlowe@gmail.com>
To: Alexy Khrabrov <deliverable@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: two memory-consuming postgres processes
Date: Fri, 2 May 2008 13:30:38 -0600
Message-ID: <dcc563d10805021230i5916561k3962a41e2afa894c@mail.gmail.com> (raw)
In-Reply-To: <A728C858-76CF-473F-917B-3C9EA4AA75CF@gmail.com>
References: <A728C858-76CF-473F-917B-3C9EA4AA75CF@gmail.com>
On Fri, May 2, 2008 at 1:24 PM, Alexy Khrabrov <deliverable@gmail.com> wrote:
> Greetings -- I have an UPDATE query updating a 100 million row table, and
> allocate enough memory via shared_buffers=1500MB. However, I see two
> processes in top, the UPDATE process eating about 850 MB and the writer
> process eating about 750 MB. The box starts paging. Why is there the
> writer taking almost as much space as the UPDATE, and how can I shrink it?
Shared_buffers is NOT the main memory pool for all operations in
pgsql, it is simply the buffer pool used to hold data being operated
on.
Things like sorts etc. use other memory and can exhaust your machine.
However, I'd like to see the output of vmstat 1 or top while this is
happening.
How much memory does this machine have?
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To: pgsql-performance@postgresql.org
Cc: scott.marlowe@gmail.com, deliverable@gmail.com
Subject: Re: two memory-consuming postgres processes
In-Reply-To: <dcc563d10805021230i5916561k3962a41e2afa894c@mail.gmail.com>
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