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, <t...@fuzzy.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 > >
