Re: Postgres using more memory than it should - Mailing list pgsql-performance

From tv@fuzzy.cz
Subject Re: Postgres using more memory than it should
Date
Msg-id 61517.89.102.139.23.1228321512.squirrel@sq.gransy.com
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In response to Postgres using more memory than it should  (Matthew Wakeling <matthew@flymine.org>)
Responses Re: Postgres using more memory than it should
List pgsql-performance
>
> Hi. I have a problem on one of our production servers. A fairly
> complicated query is running, and the backend process is using 30 GB of
> RAM. The machine only has 32GB, and is understandably swapping like crazy.
> My colleague is creating swap files as quickly as it can use them up.
>
> The work_mem setting on this machine is 1000MB, running Postgres 8.3.0.

Are you aware that this is a per-session / per-sort settings? That means,
if you have 10 sessions, each of them running query with 2 sort steps in
the plan, it may occupy up to 20 GB of RAM (if both sorts use the whole
1GB of RAM).

regards
Tomas


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