Re: lazy vacuum and AccessExclusiveLock - Mailing list pgsql-general

From Alvaro Herrera
Subject Re: lazy vacuum and AccessExclusiveLock
Date
Msg-id 20090925224129.GV3914@alvh.no-ip.org
Whole thread Raw
In response to Re: lazy vacuum and AccessExclusiveLock  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: lazy vacuum and AccessExclusiveLock
List pgsql-general
Tom Lane wrote:
> Alvaro Herrera <alvherre@commandprompt.com> writes:
> > An alternative solution would be to lower the vacuum delay settings before
> > starting the truncating phase, but this doesn't work very well in autovacuum
> > due to the autobalancing code (which can cause other processes to change our
> > cost delay settings).  This case could be considered in the balancing code, but
> > it is simpler this way.
>
> I don't think autovacuum has a problem --- if someone requests a
> conflicting lock, autovac will get kicked off, no?  The OP's problem
> comes from doing a manual vacuum.  Perhaps "don't do that" is a good
> enough answer.

Hah, that was part of the commit message, which predates autovacuum
getting kicked out in case of conflicting locks IIRC.

I think the process being described is unusual enough that a manual
vacuum at just the right time is warranted ...

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

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