Josh Berkus <josh@xxxxxxxxxxxx> writes: >> -checkpoint_segments - this is crucial as one of the server is >> transaction heavy > Well, it only helps you to raise this if you have a dedicated disk resource > for the xlog. Otherwise having more segments doesn't help you much. Au contraire, large checkpoint_segments is important for write-intensive workloads no matter what your disk layout is. If it's too small then you'll checkpoint too often, and the resulting increase in page-image writes will hurt. A lot. My advice is to set checkpoint_warning to the same value as checkpoint_timeout (typically 5 minutes or so) and then keep an eye on the postmaster log for awhile. If you see more than a few "checkpoints are occuring too frequently" messages, you want to raise checkpoint_segments. regards, tom lane
