Oracle SQL Tuning with Explain Plan

Do you use EXPLAIN PLAN to tune Oracle SQL? Does it always “tell the truth”, or does it “lie”. (Maybe it’s not the whole truth!) In this free tutorial from SkillBuilders’ Oracle Certified Master John Watson, you will learn why the execution plan generated by EXPLAIN PLAN can be misleading and what to do about it. After a brief lecture, John demonstrates exactly why. You’ll hear about dynamic sampling, adaptive cursor sharing (11g), adaptive execution plans (12c) and of course, bind variables. John demonstrates how bind variables cause misleading execution plans using dbms_xplan.display and dbms_xplan.display_cursor. To get the most from this tutorial, you should have some understanding of hard parse, soft parse, cardinality, histograms.