Session
Query Optimizer Internals and What's New in the MySQL 5.2 Optimizer
Timour Katchaounov, Software Developer, MySQL
Track: Architecture and Technology
Date: Wednesday, April 25
Time: 4:40pm
- 6:15pm
Location: Ballroom F
The first part of this talk describes the main principles behind MySQL's query optimizer and execution engine, how the optimizer transforms queries into executable query plans, how these plans look, and how they are executed. The second part of the talk describes the major improvements in the query engine of MySQL 5.2, and how users could benefit from these improvements.
The most important improvement is subquery optimization. The talk describes the new optimizations, the classes of (sub)queries they cover, how these optimizations will be implemented, and examples of performance gains.
The next new feature is disk-sweep range read for MyISAM and InnoDB. The talk describes the disk-sweep range read implementation and how it can speed up query execution.
Finally we describe a number of smaller improvements that affect query optimization/execution in MySQL 5.2.