Chapter 1. Back To Basics

Many MySQL users and administrators slide into using MySQL. They hear its benefits, find that it's easy to install on their systems (or better yet, comes pre-installed), and read a quick book on how to attach simple SQL operations to web sites or other applications.

It may take several months for the dragons to raise their heads. Perhaps one particular web page seems to take forever, or a system failure corrupts a database and makes recovery difficult.

Real-life use of MySQL requires forethought and care—and a little benchmarking and testing. This book is for the MySQL administrator who has the basics down but realizes the need to go further. It's a good book to read after you've installed and learned how to use MySQL but before your site starts to get a lot of traffic, and the dragons are breathing down your neck. (When problems occur during a critical service, your fellow workers and friendly manager start to take on decidedly dragon-like appearances.)

The techniques we teach are valuable in many different situations, and sometimes to solve different problems. Replication, for instance, may be a matter of reliability for you—an essential guarantee that your site will still be up if one or two systems fail. But replication can also improve performance; we show you architectures and techniques that solve multiple problems.

We also take optimization far beyond the simple use of indexes and diagnostic (EXPLAIN) statements: this book tells you what the factors in good performance are, where bottlenecks occur, how to benchmark MySQL, and other advanced performance topics.

We ask for a little more patience and time commitment than the average introductory computer book. Our approach involves a learning cycle, and experience convinces us that it's ultimately the fastest and most efficient way to get where you want.

After describing the problems we're trying to solve in a given chapter, we start with some background explanation. In other words, we give you a mental model for understanding what MySQL is doing. Then we describe the options you have to solve the problem, and only after all that do we describe particular tools and techniques.

This book is clearly not the end of the line in terms of information. Knowing that, we've started a web site, http://www.highperformancemysql.com, where we put useful scripts and new topics. See the Preface for more information.

Before we dig into how to tune your MySQL system to optimum performance, it's best if we go over a couple of ground rules and make sure everyone is on the same page.