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autovacuum questions
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* autovacuum questions
@ 2008-10-31 15:16 Isabella Ghiurea <isabella.ghiurea@nrc-cnrc.gc.ca>
  2008-10-31 15:32 ` Re: autovacuum questions Rafael Domiciano <rafael.domiciano@gmail.com>
  0 siblings, 1 reply; 4+ messages in thread

From: Isabella Ghiurea @ 2008-10-31 15:16 UTC (permalink / raw)
  To: pgsql-admin

Hello Gurus,
I'm new to PG , running PG 8.3 on Linux and reading trough docs  is 
mentioned that in PG vers 8.3  an AUTO vacuum process   has been 
implemented which will run
full vacuum  on  all user and system tables + analyze  and there is  NO 
need fro DBA  to schedule a crontab job to run this  maintenance jobs . 
If this is true , here are my questions :
Would like to know from your experience is this automated process 
sufficient and reliable in a warehouse database , can I rely only  on 
this  internal  process ?
How can I see when the job has been run or completed by PG ?
I have configure track_count=true, what values should I go for 
autovacuum_naptime  from your experience?

Isabella




^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: autovacuum questions
  2008-10-31 15:16 autovacuum questions Isabella Ghiurea <isabella.ghiurea@nrc-cnrc.gc.ca>
@ 2008-10-31 15:32 ` Rafael Domiciano <rafael.domiciano@gmail.com>
  2008-10-31 16:02   ` Re: autovacuum questions Alvaro Herrera <alvherre@commandprompt.com>
  0 siblings, 1 reply; 4+ messages in thread

From: Rafael Domiciano @ 2008-10-31 15:32 UTC (permalink / raw)
  To: isabella.ghiurea@nrc-cnrc.gc.ca; +Cc: pgsql-admin

Hello there,

Yes, the autovacuum is set on by default on the PG 8.3.
The vacuum is not full, to run a full vacuum you need to set a cron job;
better to run at the night.
I don't set autovacuum on the production databases, only in the Slony's
slave machines and in the developmente machine.
For autovacuum settings you need to set and see if it's ok for you.
to see if the vacuum is running you can use the command "ps axf | grep
postgres" on the linux server. Sometimes autovacuum is so fast that you even
notice him.

I hope that I helped

Best Regards,

Rafael Domiciano

2008/10/31 Isabella Ghiurea <isabella.ghiurea@nrc-cnrc.gc.ca>

> Hello Gurus,
> I'm new to PG , running PG 8.3 on Linux and reading trough docs  is
> mentioned that in PG vers 8.3  an AUTO vacuum process   has been implemented
> which will run
> full vacuum  on  all user and system tables + analyze  and there is  NO
> need fro DBA  to schedule a crontab job to run this  maintenance jobs . If
> this is true , here are my questions :
> Would like to know from your experience is this automated process
> sufficient and reliable in a warehouse database , can I rely only  on this
>  internal  process ?
> How can I see when the job has been run or completed by PG ?
> I have configure track_count=true, what values should I go for
> autovacuum_naptime  from your experience?
>
> Isabella
>
>
> --
> Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-admin
>

^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: autovacuum questions
  2008-10-31 15:16 autovacuum questions Isabella Ghiurea <isabella.ghiurea@nrc-cnrc.gc.ca>
  2008-10-31 15:32 ` Re: autovacuum questions Rafael Domiciano <rafael.domiciano@gmail.com>
@ 2008-10-31 16:02   ` Alvaro Herrera <alvherre@commandprompt.com>
  2008-10-31 18:31     ` Re: autovacuum questions Scott Marlowe <scott.marlowe@gmail.com>
  0 siblings, 1 reply; 4+ messages in thread

From: Alvaro Herrera @ 2008-10-31 16:02 UTC (permalink / raw)
  To: Rafael Domiciano <rafael.domiciano@gmail.com>; +Cc: isabella.ghiurea@nrc-cnrc.gc.ca; pgsql-admin

Rafael Domiciano escribió:

> The vacuum is not full, to run a full vacuum you need to set a cron job;
> better to run at the night.

Doing VACUUM FULL on crontab is rarely a good idea.  If you find
yourself in a situation where you need VACUUM FULL, then you've not
tuned regular vacuum appropriately.

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



^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: autovacuum questions
  2008-10-31 15:16 autovacuum questions Isabella Ghiurea <isabella.ghiurea@nrc-cnrc.gc.ca>
  2008-10-31 15:32 ` Re: autovacuum questions Rafael Domiciano <rafael.domiciano@gmail.com>
  2008-10-31 16:02   ` Re: autovacuum questions Alvaro Herrera <alvherre@commandprompt.com>
@ 2008-10-31 18:31     ` Scott Marlowe <scott.marlowe@gmail.com>
  0 siblings, 0 replies; 4+ messages in thread

From: Scott Marlowe @ 2008-10-31 18:31 UTC (permalink / raw)
  To: Alvaro Herrera <alvherre@commandprompt.com>; +Cc: Rafael Domiciano <rafael.domiciano@gmail.com>; isabella.ghiurea@nrc-cnrc.gc.ca; pgsql-admin

On Fri, Oct 31, 2008 at 10:02 AM, Alvaro Herrera
<alvherre@commandprompt.com> wrote:
> Rafael Domiciano escribió:
>
>> The vacuum is not full, to run a full vacuum you need to set a cron job;
>> better to run at the night.
>
> Doing VACUUM FULL on crontab is rarely a good idea.  If you find
> yourself in a situation where you need VACUUM FULL, then you've not
> tuned regular vacuum appropriately.

There are some use cases where vacuum full is appropriate.  But
they're rare.  And they're usually better off being added to whatever
script is doing the thing that causes the database to need vacuum
full.  Certain batch processing or data loading processes need vacuum
full and or reindex when finishing.

But the common thought process on vacuum full for most people is "If
vacuum is good, vacuum full must be even better!" which is just wrong.



^ permalink  raw  reply  [nested|flat] 4+ messages in thread


end of thread, other threads:[~2008-10-31 18:31 UTC | newest]

Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2008-10-31 15:16 autovacuum questions Isabella Ghiurea <isabella.ghiurea@nrc-cnrc.gc.ca>
2008-10-31 15:32 ` Rafael Domiciano <rafael.domiciano@gmail.com>
2008-10-31 16:02   ` Alvaro Herrera <alvherre@commandprompt.com>
2008-10-31 18:31     ` Scott Marlowe <scott.marlowe@gmail.com>

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