Re: How about a option to disable autovacuum cancellation on lock conflict? - Mailing list pgsql-hackers

From Josh Berkus
Subject Re: How about a option to disable autovacuum cancellation on lock conflict?
Date
Msg-id 547E0CAF.3060306@agliodbs.com
Whole thread Raw
In response to How about a option to disable autovacuum cancellation on lock conflict?  (Andres Freund <andres@2ndquadrant.com>)
Responses Re: How about a option to disable autovacuum cancellation on lock conflict?  (Andres Freund <andres@2ndquadrant.com>)
List pgsql-hackers
On 12/02/2014 10:35 AM, Alvaro Herrera wrote:
> If the table is large, the time window for this to happen is large also;
> there might never be a time window large enough between two lock
> acquisitions for one autovacuum run to complete in a table.  This
> starves the table from vacuuming completely, until things are bad enough
> that an emergency vacuum is forced.  By then, the bloat is disastrous.
> 
> I think it's that suicide that Andres wants to disable.

A much better solution for this ... and one which would solve a *lot* of
other issues with vacuum and autovacuum ... would be to give vacuum a
way to track which blocks an incomplete vacuum had already visited.
This would be even more valuable for freeze.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com



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