Re: Strange performance degradation - Mailing list pgsql-performance

From A. Kretschmer
Subject Re: Strange performance degradation
Date
Msg-id 20091120102322.GD20234@a-kretschmer.de
Whole thread Raw
In response to Strange performance degradation  (Lorenzo Allegrucci <lorenzo.allegrucci@forinicom.it>)
Responses Re: Strange performance degradation  (Lorenzo Allegrucci <lorenzo.allegrucci@forinicom.it>)
List pgsql-performance
In response to Lorenzo Allegrucci :
>
> Hi all,
>
> I'm experiencing a strange behavior with my postgresql 8.3:
> performance is degrading after 3/4 days of running time but if I
> just restart it performance returns back to it's normal value..
> In normal conditions the postgres process uses about 3% of cpu time
> but when is in "degraded" conditions it can use up to 25% of cpu time.
> The load of my server is composed of many INSERTs on a table, and
> many UPDATEs and SELECT on another table, no DELETEs.
> I tried to run vacuum by the pg_maintenance script (Debian Lenny)
> but it doesn't help. (I have autovacuum off).

Bad idea. Really.

>
> So, my main question is.. how can just a plain simple restart of postgres
> restore the original performance (3% cpu time)?

You should enable autovacuum.

And you should run vacuum verbose manually and see the output.


Andreas
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Andreas Kretschmer
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