Re: Tuning Oracle SQL

From: Mike Whaley <MWhaley_at_PacBell.Net>
Date: 1996/12/17
Message-ID: <32B74FF8.4@PacBell.Net>#1/1

Remember that the RULE based optimizer is just deciding the path to use based on rules of thumb concerning the indexes and so forth. It DOES NOT take into consideration the size of your tables, frequency of values
(with male/female there are only two), and so forth. Therefore, if
properly coded the COST based optimizer not only has the rules of thumb, but knows about your data as well. It has the best chance of getting it right.

However, many of us have experience with the COST based optimizer making a funny decision, even with all the information. However, in my experience COST is better 95% of the time.

(not a dumb question)
Received on Tue Dec 17 1996 - 00:00:00 CST