The Practical Guide to Query Optimization for MySQL and PostgreSQL is a must read for any DBA or developer who wants to maximize resources, ship code faster, and do more to delight users.
Profiling is the science of categorizing, sorting, and ranking system work to determine where time, money, and resources are spent within the system. Profiling database workload is an essential skill for any database administrator or developer and is the first step to optimizing performance. This book is the first in a series. It teaches you the tools and techniques you’ll need to profile one or many MySQL or PostgreSQL databases. Further books will explain how to speed up the queries that you select for optimization as a result of profiling.
Check out the table of contents and download the full edition here.