Richard Neill <rn214@xxxxxxxxx> writes: > Now, I understand that increasing checkpoint_segments is generally a > good thing (subject to some limit), but doesn't that just mean that > instead of say a 1 second outage every minute, it's a 10 second outage > every 10 minutes? In recent PG versions you can spread the checkpoint I/O out over a period of time, so it shouldn't be an "outage" at all, just background load. Other things being equal, a longer checkpoint cycle is better since it improves the odds of being able to coalesce multiple changes to the same page into a single write. The limiting factor is your threshold of pain on how much WAL-replay work would be needed to recover after a crash. > Is it possible (or even sensible) to do a manual vacuum analyze with > nice/ionice? There's no support for that in PG. You could try manually renice'ing the backend that's running your VACUUM but I'm not sure how well it would work; there are a number of reasons why it might be counterproductive. Fooling with the vacuum_cost_delay parameters is the recommended way to make a vacuum run slower and use less of the machine. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
