Hi folks. I'll be preparing to use hibernate for a project i have.

I'm designing something close to a little framework for testcases (currently design phase), and want to use Hibernate to manage all the testcases and logs and everything.

And now it struck me, and i didn't manage to find an answer yet. Though I'm trying hard to make a good design, the structure of my classes are bound to change, as I'm implementing support for further extensions.

If the core structure of what i'm persisting changes (let's say I'll add later support for saving tested application state, and reverting to it), how will this go with Hibernate and the database? As i can't afford to lose the before-saved testcases and logs..

Say i have a simplified class TestCase that contains a list of Action objects, and a LogDeposit object (where i store every run's logs). I persist a couple of TestCase objects to the database, but later i want TestCase to contain another AppStateManager object. What happens when i try to load a prior "version" of this class into memory? Additional details would be helpful..

I'd really appreciate the help, it would guide me to a better understanding on how to design this thing.

PS: i've never used hibernate before, so i'd appreciate not getting into confusing details at this point

Thank you