Date: Mon, 14 Jul 2008 16:29:33 -0400
From: Alvaro Herrera <alvherre@commandprompt.com>
To: Chris Hoover <revoohc@gmail.com>
Cc: "pgsql-admin@postgresql.org Admin" <pgsql-admin@postgresql.org>
Subject: Re: 8.3 Autovacuum Questions
Message-ID: <20080714202933.GK4050@alvh.no-ip.org>
References: <1d219a6f0807141326p16d86505o84642b8d49fa6ad8@mail.gmail.com>
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Chris Hoover escribió:
> I just have a couple of quick questions about 8.3 and Autovacuum.
> 
> 1.  When autovacuum chooses to vacuum a table, the entire table is vacuumed,
> and not just a specified percentage of the table.  Correct?

Yes.

> 2.  There is no way, without turning autovacuum off, of excluding
> vacuum/analyze during a specific period of time (say during a known peak
> usage period).

Nope, no way.  (You could have a script to update the
pg_autovacuum.enabled flag, and change it using cron.)

> 3.  If I have a PostgreSQL cluster with 10 databases, does
> autovacuum_max_workers=3 mean I have a possibility of 3 total workers or 30
> workers (i.e. autovacuum_max_workers * number of db's)?

3 workers total.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.