Re: buffercache/bgwriter

Hi Thomas,

thanks, but there were no new informations in there for me.
this article
http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm I know and
others on his website.

Best...
Uwe

On 23 March 2011 15:41, <tv(at)fuzzy(dot)cz> wrote:

> > Hi,
> >
> > I have very bad bgwriter statistics on a server which runs since many
> > weeks
> > and it is still the same after a recent restart.
> > There are roughly 50% of buffers written by the backend processes and the
> > rest by checkpoints.
> > The statistics below are from a server with 140GB RAM, 32GB
> shared_buffers
> > and a runtime of one hour.
> >
> > As you can see in the pg_buffercache view that there are most buffers
> > without usagecount - so they are as free or even virgen as they can be.
> > At the same time I have 53% percent of the dirty buffers written by the
> > backend process.
>
> There are some nice old threads dealing with this - see for example
>
>
> http://postgresql.1045698.n5.nabble.com/Bgwriter-and-pg-stat-bgwriter-buffers-clean-aspects-td2071472.html
>
>
> http://postgresql.1045698.n5.nabble.com/tuning-bgwriter-in-8-4-2-td1926854.html
>
> and there even some nice external links to more detailed explanation
>
> http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm
>
> regards
> Tomas
>
>