Re: pg_buffercache - Mailing list pgsql-performance

From Merlin Moncure
Subject Re: pg_buffercache
Date
Msg-id CAHyXU0zTtZJ=rxXDTwoBxkb=BBcK36SVwyYfydiZ53__J0hUVw@mail.gmail.com
Whole thread Raw
In response to pg_buffercache  (pg noob <pgnube@gmail.com>)
List pgsql-performance
On Tue, Oct 30, 2012 at 1:34 PM, pg noob <pgnube@gmail.com> wrote:
>
> Hi all,
>
> I was wondering if it is safe to install pg_buffercache on production
> systems?

Well, why wouldn't you expect it to be safe?  Core extensions should
be mostly assumed safe unless there is a good reasons to believe
otherwise.  That said, there may be some performance impacts,  In
particular, take note:

"When the pg_buffercache view is accessed, internal buffer manager
locks are taken for long enough to copy all the buffer state data that
the view will display. This ensures that the view produces a
consistent set of results, while not blocking normal buffer activity
longer than necessary. Nonetheless there could be some impact on
database performance if this view is read often."

merlin


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