Open source systems are rapidly changing the software landscape. Information technology professionals everywhere
are taking note of the high quality, and in many cases world-class, development and support offered by open-sourcesoftware
vendors. Corporations are paying attention, because for the first time they have an alternative to commercial
proprietary software vendors. Small businesses are paying attention because open source software can significantly
lower the cost of their information systems. Individuals are paying attention because they have more choices with
more options than ever before. The majority of the underpinnings that make the Internet what it is today are based
on open source software systems, such as Linux, Apache HTTP server, BIND, Sendmail, OpenSSL, MySQL, and many
others.
The most common reason businesses use open source software is cost. Open source software, by its very nature,
reduces the total cost of ownership (TCO) and provides a viable business model on which businesses can build or
improve their markets. This is especially true of open-source database systems, as the cost of commercial proprietary
systems can easily go into tens or hundreds of thousands of dollars.
For small businesses just starting, this outlay of funds could impact its growth. For example, if a startup has to
spend a significant potion of its reserves, it may be unable to get its products to market and therefore may not be
able to gain a foothold in a highly competitive market. Open source provides startups with the opportunity to defer
their software purchases until they can afford the investment. That doesn’t mean, however, that they are building an
infrastructure out of inferior components.
Open source software once was considered by many to be limited to the hobbyist or hacker bent on subverting
the market of large commercial software companies. Although some developers may feel that they are playing
the role of David to Microsoft’s Goliath, the open source community is not about that at all. It does not profess to
be a replacement for commercial proprietary software, but rather, it proposes the open source philosophy as an
alternative. As you will see in this chapter, not only is open source a viable alternative to commercial software, but it is
also fueling a worldwide revolution in how software is developed, evolved, and marketed.

Contents at a Glance
About the Author ............................................................................................................... xix
About the Technical Reviewers ......................................................................................... xxi
Acknowledgments ........................................................................................................... xxiii
Introduction ...................................................................................................................... xxv
■■Part 1: Getting Started with MySQL Development ........................................ 1
■■Chapter 1: MySQL and The Open Source Revolution .........................................................3
■■Chapter 2: The Anatomy of a Database System ..............................................................23
■■Chapter 3: A Tour of the MySQL Source Code ..................................................................57
■■Chapter 4: Test-Driven MySQL Development .................................................................117
■■Part 2: Extending MySQL .......................................................................... 151
■■Chapter 5: Debugging ....................................................................................................153
■■Chapter 6: Embedded MySQL ........................................................................................195
■■Chapter 7: Adding Functions and Commands to MySQL ...............................................251
■■Chapter 8: Extending MySQL High Availability ..............................................................281
■■Chapter 9: Developing MySQL Plugins ..........................................................................339
■■Chapter 10: Building Your Own Storage Engine ............................................................369
■■Part 3: Advanced Database Internals ....................................................... 453
■■Chapter 11: Database System Internals ........................................................................455
■■Chapter 12: Internal Query Representation ...................................................................465