How should the random_page_cost be calculated? If our disk system does sustained sequential reads at 400MBps, a sequential page fetch will take 0.02ms. If the read seek time is 4ms, does this mean that the random_page_cost is 200 (4/0.02)? Or should we use the track-to-track seek time of 0.6ms, which would give a random_page_cost of 30? Or something else? Barry Geipel (barry@GeipelNet.com) ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)