Re: How A Select Statement Works?

The simple answer is the Optimizer will deterime the access path. The RULE and COST base optimizer can pick completly different paths, also optimization comes in 2 phases (transformation and access path analysis).

To determine the path chosen by the optimizer you are using use the EXPLAIN plan feature, although remember even with the access path it will not be clear where predicates are being eliminated.

Regards
David Russell Received on Sat Nov 29 1997 - 00:00:00 CST