Marcin Cieslak saper@saper.info writes:

From the PostgreSQL side I see one problem with nesting - we are already using savepoints to emulate MySQL's "INSERT IGNORE" and friends.\ It might be difficult to abuse that feature for something more than this. There is a class "SavepointPostgres" which is used for that.

Well, that is more of a stop-gap measure anyway. Long-term, we need to abstract out insert ignore properly into something that does a select and conditional insert, or a delete + insert, rather than rely on throwing, catching, and discarding an error.

In an ideal world, the MySQL code would do that too instead of relying on insert ignore.