How to Tune SQL with DBMS_ADVANCED_REWRITE

Tuning when You Can’t Edit the Source Code

How do you tune SQL if you don’t have access to the source code? Sometimes Oracle indexes, statistics, stored outlines, profiles or 12c directives will solve a tuning problem. However, as a last resort, you may want to add a hint. In this case DBMS_ADVANCED_REWRITE could be the solution. In this tutorial, Oracle Certified Master DBA John Watson of SkillBuilders demonstrates using DBMS_ADVANCED_REWRITE to change the SQL Oracle executes – without changing the source code!