From: Matthew T. O'Connor <matthew@zeut.net>
To: Michael Riess <mlriess@gmx.de>
Cc: pgsql-performance@postgresql.org
Subject: Re: Autovacuum / full vacuum
Date: Tue, 17 Jan 2006 09:09:02 -0500
Message-ID: <43CCFA7E.1060307@zeut.net> (raw)
In-Reply-To: <dqih4p$1clg$1@news.hub.org>
References: <dqigaf$1b98$1@news.hub.org>
<43CCC711.504@familyhealth.com.au>
<dqih4p$1clg$1@news.hub.org>
Michael Riess wrote:
> did you read my post? In the first part I explained why I don't want to
> increase the FSM that much.
I'm sure he did, but just because you don't have enough FSM space to
capture all everything from your "burst", that doesn't mean that space
can't be reclaimed. The next time a regular vacuum is run, it will once
again try to fill the FSM with any remaining free space it finds in the
table. What normally happens is that your table will never bee 100%
free of dead space, normally it will settle at some steady state size
that is small percentage bigger than the table will be after a full
vacuum. As long as that percentage is small enough, the effect on
performance is negligible. Have you measured to see if things are truly
faster after a VACUUM FULL?
Matt
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To: pgsql-performance@postgresql.org
Cc: matthew@zeut.net, mlriess@gmx.de
Subject: Re: Autovacuum / full vacuum
In-Reply-To: <43CCFA7E.1060307@zeut.net>
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