Re: plain inserts and deletes very slow - Mailing list pgsql-performance

From David Mitchell
Subject Re: plain inserts and deletes very slow
Date
Msg-id 42C887DC.40308@telogis.com
Whole thread Raw
In response to Re: plain inserts and deletes very slow  (Enrico Weigelt <weigelt@metux.de>)
Responses Re: plain inserts and deletes very slow  (Enrico Weigelt <weigelt@metux.de>)
List pgsql-performance
Did you vacuum full?

When you do lots of inserts and deletes, dead tuples get left behind.
When you vacuum, postgres will reuse those dead tuples, but if you don't
vacuum for a long time these tuples will build up lots. Even when you
vacuum in this case, the dead tuples are still there, although they are
marked for reuse. Vacuuming full actually removes the dead tuples.

If you vacuum (normal) regularly, then the number of dead tuples will
stay down, as they are regularly marked for reuse.

David

Enrico Weigelt wrote:
> * Enrico Weigelt <weigelt@metux.de> wrote:
>
> forgot to mention:
>
>     + linux-2.6.9
>     + postgres-7.4.6
>     + intel celeron 2ghz
>     + intel ultra ata controller
>     + 768mb ram
>
>
> cu


--
David Mitchell
Software Engineer
Telogis

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