Tuning Oracle SQL

Daniel S. Tow

Oracle Applications Performance and Tuning



This paper describes the SQL diagraming approach to tuning. This approach has been found to be directly useful in tuning complex SQL, and also has been found to increase understanding of how SQL is executed, such that understanding the approach greatly improves skill in tuning, even where the approach isn't directly used. Where most material on SQL tuning emphasizes how to read and control SQL execution plans, the focus of this method is how to choose the best execution plan from all the possible execution plans (which may be very numerous, and which may be mostly terrible, with no obvious best choices short of applying this method).