>I'm guessing the high bursts are checkpoints. Can you check your log > >files for pg and see if you are getting warnings about checkpoint > >frequency? You can get some mileage here by increasing wal files. > > Nope, nothing in the log. I have set: > wal_buffers=128 > checkpoint_segments=128 > checkpoint_timeout=3000 > which I thought was rather generous. Perhaps I should set it even > higher for the loads? But depending on your shared_buffer and bgwriter settings (as well as how much WAL traffic you're generating, you could still end up with big slugs of work to be done when checkpoints happen. If you set checkpoint_warning to 3001, you'll see exactly when checkpoints are happening, so you can determine if that's an issue.
I did that, and I get two log messages, seeing checkpoints happening at 316 and 147 seconds apart on my load of a 1.9 GB file. Is this "an issue"? Thanks!
