> So, on a 4 Gig machine you could divide 1G (25%) by the total possible > connections, then again by the average number of sorts you'd expect per > query / connection to get an idea. Thanks for the advice. I'll experiment with higher work_mem settings, as I am regularly doing sorts on large datasets. I imagine the default setting isn't very optimal in my case. > Did you turn off stats collection as well? That's really the major > performance issue with autovacuum, not autovacuum itself. I did turn off stats collection. I'm not sure how much of a difference it makes, but I was trying to squeeze every ounce of performance out of the database. > I.e. the cure may be worse than the disease. OTOH, if you don't delete > / update often, then don't worry about it. I hardly ever delete/update. I update regularly, but only on small tables so it doesn't make as big of a difference. I do huge inserts, which is why turning off stats/autovacuum gives me some performance benefit. I usually only do deletes nightly in large batches, so autovacuuming/analyzing once an hour works fairly well. > Haven't researched temp_buffers at all. Do you usually change temp_buffers? Mine is currently at the default setting. I guess I could arbitrarily bump it up - but I'm not sure what the consequences would be or how to tell if it is set correctly. > random_page_cost is the hardest to come up with the proper setting. This definitely sounds like the hardest to figure out. (since it seems to be almost all trial-and-error) I'll play with some different values. This is only used by the query planner right? How much of a performance difference does it usually make to tweak this number? (i.e. how much performance difference would someone usually expect when they find that 2.5 works better than 4?) > While you can't > change buffers on the fly, you can change work_mem and random_page_cost > on the fly, per connection, to see the change. Thanks for the advice. I was aware you could change work_mem on the fly, but didn't think about setting random_page_cost on-the-fly.
