With a "first look" at one of the powerful new features of MySQL 5 (alpha), John Lim of PHPEverywhere looks at the MySQL 5 triggers.

Peter Guluten talks about the new trigger feature of MySQL 5. If the following is correct, this is a serious limitation compared to competing databases:

MySQL functions have severe limitations. For example, they can't SELECT from a table. Trigger activations are like function calls and are subject to the same limitations.

His posting over on the O'Reilly Network does worry me a bit too. Though there is a bright note to consider: triggers work for both INSERT and UPDATE, that trigger bodies can contain complex statements, and that BEFORE triggers can read and change the values that I'm inserting or updating.