Well, the first thing you want to do when you finish a book like this is go on and on about how impressed you are. This is one of the best database technology books I've read, and the best one on MySQL.
Digging into the book I would say I was an intermediate DBA. With 12 years experience on Oracle I was a seasoned DBA. And although I've used MySQL for about 10 years, I had not used all of the high end or newest 5.0 and 5.1 features. After reading this book, or while reading it, you'll be ready to dig into everything from MySQL master-master replication (not to be confused with multi-master), creating a logging server, optimizing your query cache, or even using some of the Google MySQL patches to add some much needed but missing feature to MySQL.
The book is organized pretty well. Keep in mind that this is not a beginner book. If you're looking for more general across the board MySQL book, I'd recommend the APress Pro MySQL by Kruckenberg and Pipes Pro MySQL (Expert's Voice in Open Source). It is also very good, but hits more of the beginning topics (as well as some advanced ones). So given the intermediate to advanced audience, this book dives right into benchmarking and profiling at the beginning.
Queries... those pesky SQL commands that you send to your database. They're so important to performance, yet so sadly misunderstood. This book devotes two chapters to the topic, one about schema and index optimization, and one about query performance. These two work together. You need to understand indexing to make best use of them, and how to write good queries to get only the data you need. The indexing chapter hit on index types supported by MyISAM, and ones for InnoDB. It talked about rebuilding, and when it's important, and statistics, and how they are different across the different storage engines. And this is a key point. Going into this book with my Oracle background, I had a lot of questions about how the optimizing engine aka the cost-based optimizer, works and interacts with the storage engines. It's all laid out here in clear detail. It was pretty obvious that these others are closely involved with the actual database development, and/or interviewed some of them to get the information correct. This is something I've had a hard time finding in other books, and really key to understanding how to optimize and tune queries. Where does the query cache sit, when and how are queries parsed, when does the optimizer pickup statistics, and how does it use them. You'll learn all the ins and outs of the explain facility, which you'll of course need to know to tune queries.
The next chapter on advanced features covered the query cache in detail, how to set it up, how to tune it, and how to monitor it. The chapter also covers UDFs, cursors, stored procedures, views, full-text searching, merge tables, partitioning and so on. One other topic it really investigated was distributed (XA) transactions. You might at first think these are an advanced topic that most users don't need to know about unless your application uses them. After all, who needs to query tables in a remote database when your application can connect and do that? Well it turns out MySQL is using XA transactions internally all the time within it's storage engine architecture. One case is when you have a transaction which uses two storage engines, ie tables with different storage engine attributes. But that's not all. MySQL also treats the binary log mechanism to be a storage engine in it's own right, so interaction between your InnoDB table transactions, and the binary log is effectively an XA transaction.
The next two chapters talk about server settings, and optimizing the OS and Hardware. All important topics, and given substantial coverage. Hand these chapters to your storage engine guru, system administrator or read them yourself if you wear all those hats!
A chapter on Replication, of course we expected to find a. What you'll be glad about is that it's 65 pages of the nuts and bolts of using replication after the five minutes it took you to set it up in MySQL. It'll help you keep your databases in sync, and help you identify them when they're not. What, my replication slaves might be out of sync? There is also coverage of the new row-based replication, and how it may help alleviate many of the current limitations of MySQL replication. There is also solid coverage of various replication topologies, from single master and many slaves, to distributed master, master-master, and how to create a logging server. You'll also learn why MySQL doesn't support multi-master replication, which is where both masters received updates, and are forced to resolve conflicts, and a whole host of new problems.
After that come a few chapters on topics outside the database tier, but equally important, from load balancing, to HA, tuning your webserver to caching and so on.
The finishing chapters include backup, security, and using the built-in server status commands. And finally a chapter on other tools for interacting with and monitoring your MySQL database.
Ok, great... a wonderful book. Any criticisms. Well I save those for last because they're really minor. If you read the book cover-to-cover you'll probably take notes like I did, so you'll be doing your own summarization. But at the end of various chapters, so chock full of new and very useful information, I sometimes wished there was exactly that, a summary of the topics, and quick list of bulletpoints. That would give one an easy way to look up advice for tuning specific areas and so on.
All-in-all though this book is really a tour de force for understanding MySQL database technology. Go get a copy!