From: Tom Lane <tgl@sss.pgh.pa.us>
To: Martin Lesser <ml-pgsql@bettercom.de>
Cc: pgsql-performance@postgresql.org
Subject: Re: Vacuum becomes slow
Date: Thu, 30 Jun 2005 09:31:01 -0400
Message-ID: <18107.1120138261@sss.pgh.pa.us> (raw)
In-Reply-To: <877jgci9yh.fsf@nb-acer.bettercom.de>
References: <877jgci9yh.fsf@nb-acer.bettercom.de>
Martin Lesser <ml-pgsql@bettercom.de> writes:
> the time needed for a daily VACUUM on a table with about 28 mio records
> increases from day to day.
My guess is that the original timings were artificially low because the
indexes were in nearly perfect physical order, and as that condition
degrades over time, it takes longer for VACUUM to scan them. If that's
the right theory, the runtime should level off soon, and maybe you don't
need to do anything. You could REINDEX periodically but I think the
time taken to do that would probably be more than you want to spend
(especially since REINDEX locks out writes where VACUUM does not).
You should check that your FSM settings are large enough, but given that
the table itself doesn't seem to be bloating, that's probably not the
issue.
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, ml-pgsql@bettercom.de
Subject: Re: Vacuum becomes slow
In-Reply-To: <18107.1120138261@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox