"This series describes why it makes sense to move a PHP application to DB2, how to prepare for the migration, how to execute it, how to support it, and how to handle potential risks based on the authors' experience with a recent migration. Many code and configuration samples are provided, as well as pointers to resources to help the project run smoothly".The first part in the series was published two weeks ago.
Another added benefit, budget-wise, is that DB2 Express (Fixed Term License) is 2.5x cheaper than the equivalent MySQL version!. IBM reduced DB2 Express license cost to US$1,990 a few months ago. At around the same time, Oracle raised MySQL's price to about US$5,000.