Re: shared_buffers advice - Mailing list pgsql-performance

From Greg Stark
Subject Re: shared_buffers advice
Date
Msg-id 407d949e1003160751i43aaa472j4f90c4cf92a1e011@mail.gmail.com
Whole thread Raw
In response to Re: shared_buffers advice  ("Pierre C" <lists@peufeu.com>)
List pgsql-performance
On Tue, Mar 16, 2010 at 1:48 PM, Pierre C <lists@peufeu.com> wrote:
> Actually, I meant that in the case of a seq scan, PG will try to use just a
> few buffers (a ring) in shared_buffers instead of thrashing the whole
> buffers. But if there was actually a lot of free space in shared_buffers, do
> the pages stay, or do they not ?

They don't. The logic only kicks in if the table is expected to be >
1/4 of shared buffers though.

--
greg

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