Re: [PERFORM] DELETE taking too much memory

From: Vincent de Phily
Subject: Re: [PERFORM] DELETE taking too much memory
Date: ,
Msg-id: 6960221.CJCJgSSb5M@moltowork
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In response to: Re: [PERFORM] DELETE taking too much memory  ("French, Martin")
List: pgsql-general

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DELETE taking too much memory  (vincent dephily, )
 Re: [PERFORM] DELETE taking too much memory  ("French, Martin", )
  Re: [PERFORM] DELETE taking too much memory  (Vincent de Phily, )
 Re: DELETE taking too much memory  (Guillaume Lelarge, )
  Re: DELETE taking too much memory  (Dean Rasheed, )
   Re: DELETE taking too much memory  (Vincent de Phily, )
    Re: DELETE taking too much memory  (Dean Rasheed, )
     Re: [PERFORM] DELETE taking too much memory  (Claudio Freire, )
   Re: [PERFORM] DELETE taking too much memory  (Jose Ildefonso Camargo Tolosa, )
  Re: DELETE taking too much memory  (Vincent de Phily, )
 Re: [PERFORM] DELETE taking too much memory  (Vincent de Phily, )
 Re: [PERFORM] DELETE taking too much memory  ("French, Martin", )

On Thursday 07 July 2011 19:54:08 French, Martin wrote:
> How up to date are the statistics for the tables in question?
>
> What value do you have for effective cache size?
>
> My guess would be that planner thinks the method it is using is right
> either for its current row number estimations, or the amount of memory
> it thinks it has to play with.

Not very up to date I'm afraid (as shown by the low estimate of deleted rows).
Table t2 has been insert-only since its re-creation (that's another story),
while t1 is your classic insert-many, update-recent.

We haven't tweaked effective cache size yet, it's on the TODO... like many
other things :/
--
Vincent de Phily


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