Already Running Another RDBMS?

If you're currently running another database system, should you convert to MySQL? Not necessarily. If you're happy with your current system, why bother to switch? But if you feel constrained by what you're using, you definitely should consider MySQL. Perhaps performance of your current system is a concern, or it's proprietary and you don't like being locked into it. Perhaps you'd like to run on hardware that's not supported by your current system, or your software is provided in binary-only format and you'd really prefer to have the source available. Or maybe it just costs too much! All of these are reasons to look into MySQL. Use this book to familiarize yourself with MySQL's capabilities, ask some questions on the MySQL mailing list, and you'll probably find the answers you need to make a decision.

If you are considering switching from another SQL database to MySQL, check out the comparison page on the MySQL Web site at http://www.mysql.com/information/crash-me.php. Then check the chapters in this book that deal with MySQL's data types and dialect of SQL.You may decide that the version of SQL supported by your current RDBMS is too different and that porting your applications would involve significant effort.

Part of your evaluation should be to try porting a few examples, of course, because it may turn out not to be as difficult as you think even if your database is an older one that doesn't understand SQL. One such experience I've had required converting a record management system from an RDBMS that wasn't SQL-based. There wasn't any language similarity at all to take advantage of, and some of the data types had no SQL equivalent. This project involved conversion of the network access methods and dozens of screen-based entry programs and canned queries. It took perhaps a month and a half of full-time effort. That's not bad.