Re: Bug: Buffer cache is not scan resistant - Mailing list pgsql-hackers

From Jeff Davis
Subject Re: Bug: Buffer cache is not scan resistant
Date
Msg-id 1173125554.13722.318.camel@dogma.v10.wvs
Whole thread Raw
In response to Re: Bug: Buffer cache is not scan resistant  (Hannu Krosing <hannu@skype.net>)
List pgsql-hackers
On Mon, 2007-03-05 at 11:10 +0200, Hannu Krosing wrote:
> > My proposal for a fix: ensure that when relations larger (much larger?)
> > than buffer cache are scanned, they are mapped to a single page in the
> > shared buffer cache.
> 
> How will this approach play together with synchronized scan patches ?
> 

Thanks for considering my patch in this discussion. I will test by
turning shared_buffers down as low as I can, and see if that makes a big
difference.

> Or should synchronized scan rely on systems cache only ?
> 

I don't know what the performance impact of that will be; still good
compared to reading from disk, but I assume much more CPU time.

Regards,Jeff Davis



pgsql-hackers by date:

Previous
From: Jeff Davis
Date:
Subject: Re: Bug: Buffer cache is not scan resistant
Next
From: Heikki Linnakangas
Date:
Subject: Re: Time-correlated columns in large tables