Re: checkpoint segments

From: Alvaro Herrera <alvherre(at)surnet(dot)cl>
To: Josh Berkus <josh(at)agliodbs(dot)com>
Cc: David Parker <dparker(at)tazznetworks(dot)com>, pgsql-performance(at)postgresql(dot)org
Subject: Re: checkpoint segments
Date: 2005-05-16 04:40:53
Message-ID: 20050516044053.GB9292@surnet.cl
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: 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)

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Mindaugas Riauba 2005-05-16 10:05:04 Re: PostgreSQL strugling during high load
Previous Message Alvaro Herrera 2005-05-16 04:39:20 Re: checkpoint segments