Re: Problems with autovacuum

From: Alvaro Herrera
Subject: Re: Problems with autovacuum
Date: ,
Msg-id: 20090526181934.GG32650@alvh.no-ip.org
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In response to: Re: Problems with autovacuum  (Tom Lane)
Responses: Re: Problems with autovacuum  (Tom Lane)
List: pgsql-performance

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Problems with autovacuum  (Łukasz Jagiełło, )
 Re: Problems with autovacuum  (Scott Marlowe, )
  Re: Problems with autovacuum  (Grzegorz Jaśkiewicz, )
   Re: Problems with autovacuum  (Scott Marlowe, )
   Re: Problems with autovacuum  (Łukasz Jagiełło, )
    Re: Problems with autovacuum  (Tom Lane, )
     Re: Problems with autovacuum  (Łukasz Jagiełło, )
     Re: Problems with autovacuum  (Alvaro Herrera, )
      Re: Problems with autovacuum  (Tom Lane, )
       Re: Problems with autovacuum  (Alvaro Herrera, )
        Re: Problems with autovacuum  (Tom Lane, )
         Re: Problems with autovacuum  (Alvaro Herrera, )
          Re: Problems with autovacuum  (Tom Lane, )
           Re: Problems with autovacuum  (Alvaro Herrera, )
            Re: Problems with autovacuum  (Tom Lane, )
             Re: Problems with autovacuum  (Scott Marlowe, )
             Re: Problems with autovacuum  (Alvaro Herrera, )
              Re: Problems with autovacuum  (Tom Lane, )
               Re: Problems with autovacuum  (Alvaro Herrera, )
                Re: Problems with autovacuum  (Alvaro Herrera, )
                Re: Problems with autovacuum  (Tom Lane, )
       Re: Problems with autovacuum  (Łukasz Jagiełło, )
  Re: Problems with autovacuum  (Łukasz Jagiełło, )
   Re: Problems with autovacuum  (Grzegorz Jaśkiewicz, )

Tom Lane escribió:
> =?UTF-8?B?xYF1a2FzeiBKYWdpZcWCxYJv?= <> writes:
> > That autovacuum working hole time, shoudn't be run only when db needs ?
>
> With 2000 databases to cycle through, autovac is going to be spending
> quite a lot of time just finding out whether it needs to do anything.
> I believe the interpretation of autovacuum_naptime is that it should
> examine each database that often, ie once a minute by default.  So
> it's got more than 30 databases per second to look through.

Note that this is correct in 8.1 and 8.2 but not 8.3 onwards.

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


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