> I don't think it's a bad idea, I just think you have to set your > expectations pretty low. If the estimates are bad there isn't really > any plan that will be guaranteed to run quickly.
Well, the way to do this is via a risk-confidence system. That is, each operation has a level of risk assigned to it; that is, the cost multiplier if the estimates are wrong. And each estimate has a level of confidence attached. Then you can divide the risk by the confidence, and if it exceeds a certain level, you pick another plan which has a lower risk/confidence level. However, the amount of extra calculations required for even a simple query are kind of frightning. -- Josh Berkus PostgreSQL Experts Inc. www.pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
