Session
EXPLAIN Demystified

January 11th, 2012 @ 10:55AM

Abstract

If you don't understand MySQL's EXPLAIN output, this session is for you. EXPLAIN output is confusing, but if you understand how it's created, it'll make sense to you.

You'll leave this session with the knowledge necessary to understand the most complex query plans, including those with filesorts, subqueries, and UNIONs. You'll see the internals of MySQL from a new angle. That knowledge will prepare you to reason about query execution plans the same way the MySQL server does. As a result, you'll be able to write queries that get the best performance from MySQL's query optimizer and executioner.

Tracks: DBA, Developer

Level: Advanced

Speaker

Baron Schwartz

Chief Performance Architect, Percona

Baron is the lead author of High Performance MySQL, and creator of Maatkit. He consults with Percona's customers, and develops tools and practices for Percona's team.