On Fri, Nov 4, 2011 at 1:26 PM, Kevin Grittner <Kevin.Grittner@xxxxxxxxxxxx> wrote: > As already pointed out, SELECT FOR UPDATE will require a disk write > of the tuple(s) read. If these are glutting, increasing > shared_buffers would tend to make things worse. I thought shared_buffers improved write caching. We do tend to write onto the same rows over and over. > Hopefully you have a BBU RAID controller configured for write-back. > If not you should. If you do, another thing which might help is > increasing the cache on that controller. Write-back on the RAID is another issue. The controller is old and has a very small cache, we're already in the process of securing a replacement. > Or you could move WAL to a > separate file system on a separate controller with its own BBU > write-back cache. WAL is already on a separate controller and array. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
