Lukas Smith, in his latest blog entry spotlights a feature added a while back to the MDB2 database package he develops - the ability to disable the execution of SQL queries.

A long while ago I added a seemingly idiotic feature to MDB2: The ability to disable the execution of queries.

The idea was that with the combination of a debug handler it would be possible for people to create a dump of SQL queries generated by MDB2_Schema during the installation or updating of a schema. All you would need to do is write up a debug handler for MDB2. Finally you would set the "disable_query" parameter when calling MDB2_Schema::updateDatabase() to true.

He also includes some brief code and some notes about the further development of the idea and its inclusion into other apps (LiveUser). There's also some sample output from one of his scripts to give you an idea of what the end result will be.