Kelly Burkhart <kelly@xxxxxxxxxxxxxxxxxxx> writes: > ... A graph showing the performance > characteristics is here: > <http://kkcsm.net/pgcpy.jpg> I hadn't looked at this chart till just now, but it sure seems to put a crimp in my theory that you are running out of room to hold the indexes in RAM. That theory would predict that once you fall over the knee of the curve, performance would get steadily worse; instead it gets markedly worse and then improves a bit. And there's another cycle of worse-and-better around 80M rows. I have *no* idea what's up with that. Anyone? Kelly, could there be any patterns in the data that might be related? The narrow spikes look like they are probably induced by checkpoints. You could check that by seeing if their spacing changes when you alter checkpoint_segments and checkpoint_timeout. It might also be entertaining to make the bgwriter parameters more aggressive to see if you can ameliorate the spikes. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
