Claudio Freire <klaussfreire@xxxxxxxxx> wrote: > Now, I'm thinking those writes are catching the DB at a bad moment - > we do have regular very write-intensive peaks. > > Maybe I should look into increasing shared buffers? 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. You might want to make the background writer more aggressive or *reduce* shared_buffers to better spread the output. 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. Or you could move WAL to a separate file system on a separate controller with its own BBU write-back cache. -Kevin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
