I have a legacy system still on 7.4 (I know, I know...the upgrade is coming soon). I have a fairly big spike happening once a day, every day, at the same time. It happens during a checkpoint, no surprise there. I know the solution to the problem (upgrade to a modern version), but what I'm looking for as an explanation as to why one particular checkpoint would be so bad on a low volume system, so I can appease certain management concerns. This is a _really _low volume system, less than 500 writes/hour. Normal operation sees checkpoint related spikes of around 200-300 milliseconds. We always checkpoint at the checkpoint timeout (every 5 minutes). During this one checkpoint, I'm seeing transactions running 2-3 seconds. During this time, writes are < 5/minute. Relevant settings: shared_buffers = 10000 checkpoint_segments = 30 checkpoint_timeout = 300 What gives? -- Brad Nicholson 416-673-4106 Database Administrator, Afilias Canada Corp. ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
