odb-orm

I am looking into using an ORM (Objection Relational Mapper) to allow me to persist my C++ objects into an SQLite database. I'm currently considering ODB by CodeSynthesis. See: http://www.codesynthesis.com/products/odb/ Looking at the docs for ODB, I don't see an answer to a nagging question I have, which is: What happens if I create a class, persist it to the DB, but then in a later version of my product change the class. When the user gets the new version of my software, how will the old data get loaded properly into the new version of the class? I've looked at boost::serialize before and it