SQL Tuning - Rule-Based Optimizer Tuning

SQL Tuning - Rule-Based Optimizer Tuning  : The rule-based optimizer provides a good deal of scope for tuning. Because its behavior is predictable, governed by the 20 condition rankings, we are able to manipulate its choices. Although this manipulation can be very rewarding, it is generally difficult and confusing to the uninitiated. The first thing to do is to become familiar with the normal workings of the rule-based optimizer. Investigate and understand how the optimizer makes its decisions; how the creation and/or removal of an index influences the decision process, why a UNIQUE index has precedent over a non-UNIQUE index, etc. This information is all explained in your basic Oracle tuning manuals. But you can go still further.