Although MySQL's source code is open in the sense of being publicly available, it's essentially closed to you if you don't understand it. In this book, Sasha Pachev - a former member of the MySQL Development Team - provides a comprehensive tour of MySQL 5 that shows you how to figure out the inner workings of this powerful database. You'll go right to heart of the database to learn how data structures and convenience functions operate, how to add new storage engines and configuration options, and much more. The core of "Understanding MySQL Internals" begins with an Architecture Overview that provides a brief introduction of how the different components of MySQL work together. You then learn the steps for setting up a working compilable copy of the code that you can change and test at your pleasure. Other sections of the book cover: core server classes, structures, and API; the communication protocol between the client and the server; configuration variables, the controls of the server; includes a tutorial on how to add your own; thread-based request handling - understanding threads and how they are used in MySQL; an overview of MySQL storage engines; the storage engine interface for integrating third-party storage engines; the table lock manager; the parser and optimizer for improving MySQL's performance; integrating a transactional storage engine into MySQL; and the internals of replication. "Understanding MySQL Internals" provides unprecedented opportunities for developers, DBAs, database application programmers, IT departments, software vendors, and computer science students to learn about the inner workings of this enterprise-proven database. With this book, you will soon reach a new level of comprehension regarding database development that will enable you to accomplish your goals. It's your guide to discovering and improving a great database.