Re: Bloat issue on 8.3; autovac ignores HOT new pages?

От: Mark Kirkwood
Тема: Re: Bloat issue on 8.3; autovac ignores HOT new pages?
Дата: ,
Msg-id: 4D48993A.30207@catalyst.net.nz
(см: обсуждение, исходный текст)
Ответ на: Re: Bloat issue on 8.3; autovac ignores HOT new pages?  (Scott Marlowe)
Список: pgsql-performance

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Bloat issue on 8.3; autovac ignores HOT page splits?  (Josh Berkus, )
 Re: Bloat issue on 8.3; autovac ignores HOT page splits?  (Robert Haas, )
  Re: Bloat issue on 8.3; autovac ignores HOT page splits?  (Josh Berkus, )
   Re: Bloat issue on 8.3; autovac ignores HOT page splits?  (Mark Kirkwood, )
    Re: Bloat issue on 8.3; autovac ignores HOT new pages?  (Josh Berkus, )
     Re: Bloat issue on 8.3; autovac ignores HOT new pages?  (Mark Kirkwood, )
     Re: Bloat issue on 8.3; autovac ignores HOT new pages?  (Scott Marlowe, )
      Re: Bloat issue on 8.3; autovac ignores HOT new pages?  (Mark Kirkwood, )

On 01/02/11 10:57, Scott Marlowe wrote:
On Mon, Jan 31, 2011 at 11:27 AM, Josh Berkus <> wrote:
Robert, Mark,

I have not been able to reproduce this issue in a clean test on 9.0.  As
a result, I now think that it was related to the FSM being too small on
the user's 8.3 instance, and will consider it resolved.
I used to try and size free space map to be a little bigger than it
needed to be.  I now size 4 or 5 times what it needs to be.  shared
memory is cheap.  So is going to 8.4, but on legacy systems that you
can't upgrade, 8.3 with a huge FSM works well enough (with suitably
aggressive autovac).


Yeah, 8.3 with very aggressive autovac my experience too - I've had the naptime cranked down to 10s or even 1s in some cases, to try to tame bloat growth for web cache or session type tables that are heavily volatile.

regards

Mark

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