Re: Clarification Needed: When does autovacuum daemon run?

Thanks Devrim and Ian, for a quick response.

I need some more clarification. autovacuum_naptime takes one minute by default. In this case, which second of each minute the autovacuum daemon runs (provided it is enabled)? What is the "activity rounds" mentioned in the manual?

Regards, Narasimha Murthy
Cell +91 95814 98895, +91-94940 62794 | 040-2347 2025 (O) | x2025 (O)

-----Original Message-----
From: Ian Lea [mailto:ian(dot)lea(at)gmail(dot)com]
Sent: Tuesday, May 18, 2010 3:43 PM
To: Narasimha Murthy-VRFX87
Subject: Re: [ADMIN] Clarification Needed: When does autovacuum daemon run?

As far as I understand it, the idea of autovacuum is that it chugs away transparently in the background, keeping things healthy on a little but often basis. It is not designed to run once a day at a specific time. If that is really what you want, I suggest you disable autovacuum and run vacuum manually at 05:00.

--
Ian.

On Tue, May 18, 2010 at 10:56 AM, Narasimha Murthy-VRFX87 <VRFX87(at)motorola(dot)com> wrote:
> Hello,
>
> Postgresql-8.2 manual has mentioned following points.
> * The autovacuum daemon, when enabled, runs every autovacuum_naptime
> seconds.
> * autovacuum_naptime (integer): Specifies the delay between "activity
> rounds" for the autovacuum daemon....The delay is measured in seconds,
> and the default is one minute (1m)....
>
> My Query: I want to run autovacuum daemon everyday at 5 am. By setting
> autovacuum_naptime to 24*60*60 (# of seconds in a day), I can run the
> daemon everyday. But, how do I ensure the daemon runs at 5am? What is
> the "activity rounds" mentioned in the manual? Pl clarify. Appreciate an early reply.
>
> [postgresql-8.2-US.pdf]
> http://www.postgresql.org/files/documentation/pdf/8.2/postgresql-8.2-U
> S.pdf
>
> Regards, Narasimha Murthy
> Cell +91 95814 98895, +91-94940 62794 | 040-2347 2025 (O) | x2025 (O)
>