Explaining the Explain Plan: Interpreting Execution Plans for SQL Statements

Presenter: Maria Colgan, Oracle Corporation

The execution plan for a SQL statement can often seem complicated and hard to understand. Determining if the execution plan you are looking at is the best plan you could get or attempting to improve a poorly performing execution plan can be a daunting task, even for the most experienced DBA or developer. This session examines the different aspects of an execution plan, from selectivity to parallel execution, and explains what information you should be gleaming from the plan and how it affects the execution. It offers insight into what caused the Optimizer to make the decision it did as well as a set of corrective measures that can be used to improve each aspect of the plan.