От: Decibel!
Тема: Re: Vacuum looping?
Дата: ,
Msg-id: D494F6AB-F9C7-4A61-B050-181BEE320312@decibel.org
(см: обсуждение, исходный текст)
Ответ на: Re: Vacuum looping?  ("Steven Flatt")
Список: pgsql-performance

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Vacuum looping?  ("Steven Flatt", )
 Re: Vacuum looping?  (Tom Lane, )
 Re: Vacuum looping?  ("Jim C. Nasby", )
  Re: Vacuum looping?  ("Steven Flatt", )
   Re: Vacuum looping?  (Decibel!, )

On Jul 30, 2007, at 9:04 AM, Steven Flatt wrote:
> On 7/28/07, Jim C. Nasby <> wrote: What are your
> vacuum_cost_* settings? If you set those too aggressively
> you'll be in big trouble.
>
> autovacuum_vacuum_cost_delay = 100

Wow, that's *really* high. I don't think I've ever set it higher than
25. I'd cut it way back.

> autovacuum_vacuum_cost_limit = 200
>
> These are generally fine, autovacuum keeps up, and there is minimal
> impact on the system.
>
> vacuum_cost_delay = 100
> vacuum_cost_limit = 1000
>
> We set this cost_limit a little higher so that, in the few cases
> where we have to intervene manually, vacuum runs faster.

IIRC, when the cost delay was initially introduced (8.0), someone did
testing and decided that the cost limit of 200 was optimal, so I
wouldn't go changing it like that without good reason.

Normally, I'll use a delay of 10ms on good disk hardware, and 20ms on
slower hardware.
--
Decibel!, aka Jim Nasby                        
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)




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