>> Wouldn't increasing the length between checkpoints result in the >> checkpoint process taking even longer to complete? > > You don't really care how long it takes. What you want is for it not to > be chewing a bigger fraction of your I/O bandwidth than you can spare. > Hence, you want it to take longer. Trying to shorten it is just going > to make the spike worse. > > regards, tom lane > I bumped the segments up to 15, and the timeout up to 10 minutes, and changed the completion target to .7. What I observe now is that I get a short (1-2 second) period where I get slow queries - I'm running about 30 queries in parallel at any given time - it appears that all 30 queries get paused for a couple of seconds at the moment that a checkpoint begins. However, after the initial slowdown, I don't get any additional slow queries logged while the checkpoint process runs. My takeaway is that starting the checkpoint process is really expensive - so I don't want to start it very frequently. And the only downside to longer intervals between checkpoints is a longer recovery time if the system crashes? Thanks, Dan -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
