On Thu, Jul 12, 2012 at 9:07 AM, Ants Aasma <ants@xxxxxxxxxxx> wrote: > On Thu, Jul 12, 2012 at 3:48 PM, Yan Chunlu <springrider@xxxxxxxxx> wrote: >> yes the system seems overloaded, I am dealing with a simple "INSERT" but not >> sure if it is normal that it took more time than the explain estimated: > > The estimated cost is in arbitrary units, its purpose is to compare > different execution plans, not estimate time taken. So it's completely > normal that it doesn't match actual time taken. Right. And to make explicit what you implied, when there is only one to do something (like insert a row, or do maintenance on an index) it often doesn't even attempt to cost that at all as there is no choice. So it is not just a matter of units. Cheers, Jeff -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
