Re: checkpoint segments - Mailing list pgsql-performance

From Alvaro Herrera
Subject Re: checkpoint segments
Date
Msg-id 20050516044053.GB9292@surnet.cl
Whole thread Raw
In response to Re: checkpoint segments  (Josh Berkus <josh@agliodbs.com>)
Responses Re: checkpoint segments
List pgsql-performance
On Sun, May 15, 2005 at 08:26:02PM -0700, Josh Berkus wrote:
> David,
>
> > I've seen these messages in the log before, and am aware of the need to
> > increase checkpoint_segments, but I wasn't aware that recycling a
> > transaction log could be that damaging to performance. There may have
> > been some local hiccup in this case, but I'm wondering if recycling is
> > known to be a big hit in general, and if I should strive to tune so that
> > it never happens (if that's possible)?
>
> Yes, and yes.   Simply allocating more checkpoint segments (which can eat a
> lot of disk space -- requirements are 16mb*(2 * segments +1) ) will prevent
> this problem.

Hmm?  I disagree -- it will only make things worse when the checkpoint
does occur.

--
Alvaro Herrera (<alvherre[a]surnet.cl>)
"Lo esencial es invisible para los ojos" (A. de Saint Exúpery)

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