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8.3 Autovacuum Questions
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* 8.3 Autovacuum Questions
@ 2008-07-14 20:26 Chris Hoover <revoohc@gmail.com>
  2008-07-14 20:29 ` Re: 8.3 Autovacuum Questions Alvaro Herrera <alvherre@commandprompt.com>
  0 siblings, 1 reply; 3+ messages in thread

From: Chris Hoover @ 2008-07-14 20:26 UTC (permalink / raw)
  To: pgsql-admin

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?

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).

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)?

Thanks,

Chris

^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: 8.3 Autovacuum Questions
  2008-07-14 20:26 8.3 Autovacuum Questions Chris Hoover <revoohc@gmail.com>
@ 2008-07-14 20:29 ` Alvaro Herrera <alvherre@commandprompt.com>
  2008-07-14 20:34   ` Re: 8.3 Autovacuum Questions Chris Hoover <revoohc@gmail.com>
  0 siblings, 1 reply; 3+ messages in thread

From: Alvaro Herrera @ 2008-07-14 20:29 UTC (permalink / raw)
  To: Chris Hoover <revoohc@gmail.com>; +Cc: pgsql-admin

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.



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: 8.3 Autovacuum Questions
  2008-07-14 20:26 8.3 Autovacuum Questions Chris Hoover <revoohc@gmail.com>
  2008-07-14 20:29 ` Re: 8.3 Autovacuum Questions Alvaro Herrera <alvherre@commandprompt.com>
@ 2008-07-14 20:34   ` Chris Hoover <revoohc@gmail.com>
  0 siblings, 0 replies; 3+ messages in thread

From: Chris Hoover @ 2008-07-14 20:34 UTC (permalink / raw)
  To: Alvaro Herrera <alvherre@commandprompt.com>; +Cc: pgsql-admin

On Mon, Jul 14, 2008 at 4:29 PM, Alvaro Herrera <alvherre@commandprompt.com>
wrote:

> 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.
>

Alvaro,

Thanks a bunch for the concise answers.  That is exactly what we needed to
confirm.

Chris

^ permalink  raw  reply  [nested|flat] 3+ messages in thread

end of thread, other threads:[~2008-07-14 20:34 UTC | newest]

Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2008-07-14 20:26 8.3 Autovacuum Questions Chris Hoover <revoohc@gmail.com>
2008-07-14 20:29 ` Alvaro Herrera <alvherre@commandprompt.com>
2008-07-14 20:34   ` Chris Hoover <revoohc@gmail.com>

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