On 1/26/07, Alvaro Herrera <[EMAIL PROTECTED]> wrote:
Heikki Linnakangas wrote: > I'd like to see still more evidence that it's a problem before we start > changing that piece of code. It has served us well for years. So the TODO could be "investigate whether caching pg_clog and/or pg_subtrans in local memory can be useful for vacuum performance".
As Heikki suggested, we should also investigate the same for normal backends as well. It would also be interesting to investigate whether early setting of hint bits can reduce subsequent writes of blocks. A typical case would be a large table being updated heavily for a while, followed by SELECT queries. The SELECT queries would set hint bits for the previously UPDATEd tuples (old and new versions) and thus cause subsequent writes of those blocks for what could have been read-only queries. Thanks, Pavan EnterpriseDB http://www.enterprisedb.com