On 30/01/2011, at 12:27, Craig Ringer wrote:
OK, so you're pre-8.4 , which means you have the max_fsm settings to play with. Have you seen any messages in the logs about the free space map (fsm)? If your install didn't have a big enough fsm to keep track of deleted tuples, you'd face massive table bloat that a regular vacuum couldn't fix.
Ouch. You're absolutely right. There are messages about max_fsm_pages in the postgres log. It's currently set to 153600. According to the documentation, I can increase it up to 200000. Will that even help? How do I find out how many I need to set it to?
You also don't have the visibility map, which means that (auto)vacuum can't skip bits of the tables it knows don't need vacuuming. Your vacuums will be slower.
Autovacuum improved significantly in both 8.4 and 9.0; consider an upgrade.
I will consider it. Thank you.
Herouth