Best Practices in MySQL Stored Program Development

The objective of this chapter is to provide concrete, immediately applicable, quickly located advice that will assist you in writing code that is readable, maintainable, and efficient.

It might seem odd that we have written a "best practices" chapter for a language that is still in its first major release. Aren't "best practices" supposed to be determined and documented after years of trial and error, sweat, and heartache? Absolutely. Those are, in fact, precisely the kinds of best practices you will find in this chapter.

We spent more than a year between the first alpha release of MySQL 5.0 in late 2004 and the most recent production release in early 2006, learning the hard way about what works and does not work in MySQL stored programs. Beyond that, while stored programs might be new to MySQL, they have been around in other databases for yearsand both of us have plenty of experience (altogether over two decades' worth) to draw fromwith MySQL, Oracle, and SQL Server. Most of the lessons learned in developing stored programs in other languages apply directly to MySQL.

We will start off with some general-purpose guidance that is intended to assist with software development in any language, then move on to guidelines specifically crafted for the MySQL stored program language. If you find yourself reading these and saying "Well, sure, of course that is what you are supposed to do!" then we congratulate you and hope that you not only know about these best practices, but also apply them as you write your code!