Here's the scenario: We've developed a library of which uses Hibernate for it's persistence layer. It's an RSS library meant to be used by others who are building applications which need to process RSS.

The users of this library (apps that embed it, call them client apps) have additional information that needs to be persisted, much of it associated with existing Informa/Hibernate objects, some not.

How do I do that? I don't want to end up with two separate sql databases but I don't want the library to have dependency on it's clients.