. This all boils down to use. For a lot of web based sites MySQL works fine. It's free and unlike a major RDBMS doesn't require a DBA life support team (ie boring people like me :-). However, for a full blown application with multiple concurrent users with a complicated Database design, MySQL cannot be considered as a serious choice. Aside from whats been mentioned above, such as the lack of Database procs, It doesn't scale so well and the fundamental SQL is restricted for example Update statements cannot have a from clause (ANSI SQL'92 compliant but functionally very restrictive).