Re: What kind of locks does vacuum process hold on the db?

From: "Scott Marlowe" <scott(dot)marlowe(at)gmail(dot)com>
To: "Nitin Verma" <nitinverma(at)azulsystems(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: What kind of locks does vacuum process hold on the db?
Date: 2007-08-30 15:13:21
Message-ID: dcc563d10708300813p11e2f070yd09b22753230ae07@mail.gmail.com
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On 8/30/07, Nitin Verma <nitinverma(at)azulsystems(dot)com> wrote:
>
> >> Then you aren't doing regular vacuum often enough and / or don't have high
> enough fsm settings.
>
> Right now it's just default, can you please point me to a document that
> elaborates on calculation of FSM for a given load (or to say averaged load)

Run a full vacuum / reindex to reclaim the lost space.
Set up the autovacuum daemon to run.
After a day or so, vacuum all your databases, and on the last one do a
vacuum verbose.

At the end you'll have a few lines like this:

DETAIL: A total of 9612 page slots are in use (including overhead).
9612 page slots are required to track all free space.
Current limits are: 153600 page slots, 1000 relations, using 965 kB.
VACUUM

So, I'm only using about 10,000 page slots out of a maximum of 153,600 slots.

If the number of pages slots requires exceeds your current limits then
you'll need to raise them. If not, then autovacuum is doing its job.

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