Hiroki Kataoka <[EMAIL PROTECTED]> wrote: > Heikki Linnakangas wrote: > > But does it > > work for tables that have a small hot part that's updated very > > frequently? > > I think there is no problem. Bloating will make pages including the > unnecessary area which will not be accessed. Soon, those pages will be > registered into DSM.
The usage_count of pages is always incremented when the page are accessed even if they contain no useful tuples. Daed tuples in the pages are not retrieved, but the pages themselves are considered as accessed. Of cource, extra DSM-synchronizations are not needed if we assume that we need to vacuum tables less frequently than checkpoints. However, we need vacuum within 1min and set checkpoint_timeout as 15-60min in some cases. Regards, --- ITAGAKI Takahiro NTT Open Source Software Center ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate