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To: Michael Riess <mlriess@gmx.de>
cc: pgsql-performance@postgresql.org
Subject: Re: Autovacuum / full vacuum 
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Comments: In-reply-to Michael Riess <mlriess@gmx.de>
	message dated "Tue, 17 Jan 2006 11:18:59 +0100"
Date: Tue, 17 Jan 2006 10:13:41 -0500
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From: Tom Lane <tgl@sss.pgh.pa.us>
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Michael Riess <mlriess@gmx.de> writes:
> I'm curious as to why autovacuum is not designed to do full vacuum.

Locking considerations.  VACUUM FULL takes an exclusive lock, which
blocks any foreground transactions that want to touch the table ---
so it's really not the sort of thing you want being launched at
unpredictable times.

			regards, tom lane