From: Andrew Sullivan <ajs@crankycanuck.ca>
To: pgsql-performance@postgresql.org
Subject: Re: Autovacuum / full vacuum
Date: Tue, 17 Jan 2006 09:56:49 -0500
Message-ID: <20060117145649.GE21092@phlogiston.dyndns.org> (raw)
In-Reply-To: <dqigaf$1b98$1@news.hub.org>
References: <dqigaf$1b98$1@news.hub.org>
On Tue, Jan 17, 2006 at 11:18:59AM +0100, Michael Riess wrote:
> hi,
>
> I'm curious as to why autovacuum is not designed to do full vacuum. I
Because nothing that runs automatically should ever take an exclusive
lock on the entire database, which is what VACUUM FULL does.
> activity. Increasing the FSM so that even during these bursts most space
> would be reused would mean to reduce the available memory for all
> other database tasks.
I don't believe the hit is enough that you should even notice it.
You'd have to post some pretty incredible use cases to show that the
tiny loss of memory to FSM is worth (a) an exclusive lock and (b) the
loss of efficiency you get from having some preallocated pages in
tables.
A
--
Andrew Sullivan | ajs@crankycanuck.ca
The fact that technology doesn't work is no bar to success in the marketplace.
--Philip Greenspun
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To: pgsql-performance@postgresql.org
Cc: ajs@crankycanuck.ca
Subject: Re: Autovacuum / full vacuum
In-Reply-To: <20060117145649.GE21092@phlogiston.dyndns.org>
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