I delivered a presentation entitled “Parallel Execution Pitfalls and Fallacies” at an event organized by Trivadis.
Abstract: From a performance point-of-view, parallel execution is one of the most powerful features of the Enterprise Edition of Oracle Database. But, with great power comes complexity. Even though most of that complexity is hidden to the person writing SQL statements, there are specific issues I frequently see people being confronted with.
The aim of this presentation is to go over a number of pitfalls and fallacies related to topics like the index maintenance following parallel DML statements, parallel execution hints, the data distribution among parallel execution server processes, and the parallel validation of constraints.