Re: Load Distributed Checkpoints, take 3

From: Greg Smith <gsmith(at)gregsmith(dot)com>
To: Patches <pgsql-patches(at)postgresql(dot)org>
Subject: Re: Load Distributed Checkpoints, take 3
Date: 2007-06-25 21:45:37
Message-ID: Pine.GSO.4.64.0706251743540.2936@westnet.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-patches

On Mon, 25 Jun 2007, Heikki Linnakangas wrote:

> It only scans bgwriter_lru_percent buffers ahead of the clock hand. If the
> hand isn't moving, it keeps scanning the same buffers over and over again.
> You can crank it all the way up to 100%, though, in which case it would work,
> but that starts to get expensive CPU-wise.

In addition to being a CPU pig, that still won't necessarily work because
the way the LRU writer ignores things with a non-zero usage_count. If
it's dirty, it's probably been used recently as well.

--
* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD

In response to

Browse pgsql-patches by date

  From Date Subject
Next Message Greg Smith 2007-06-25 22:04:16 Re: Load Distributed Checkpoints, take 3
Previous Message Greg Smith 2007-06-25 21:43:01 Re: Load Distributed Checkpoints, take 3