Re: pg_autovacuum not having enough suction ?

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От Joshua D. Drake
Тема Re: pg_autovacuum not having enough suction ?
Дата
Msg-id 1111792626.5783.11.camel@jd2.commandprompt.com
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Ответ на Re: pg_autovacuum not having enough suction ?  (Bruce Momjian <pgman@candle.pha.pa.us>)
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> > I'm not sure if autovacuum could be taught to do that --- it could
> > perhaps launch a vacuum as soon as it notices a large fraction of the
> > table got deleted, but do we really want to authorize it to launch
> > VACUUM FULL?  It'd be better to issue the vacuum synchronously
> > as part of the batch updating script, I feel.
>
> I added this to the TODO section for autovacuum:
>
>         o Do VACUUM FULL if table is nearly empty?

We should never automatically launch a vacuum full. That seems like a
really bad idea.

Sincerely,

Joshua D. Drake


>
> I don't think autovacuum is every going to be smart enough to recycle
> during the delete, especially since the rows can't be reused until the
> transaction completes.
>
> One problem with VACUUM FULL would be autovacuum waiting for an
> exclusive lock on the table.  Anyway, it is documented now as a possible
> issue.
>
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