If I have the following hierarchy: public abstract class A {...} public class B extends A {...} public class C extends A {...} Should I be able to take an instance from the DB that maps to type B and resave it as type C? I'm using JPA so this would be a merge. I'm thinking I'm going to have to delete the existing instance and then insert the new instance, but I wanted to see if Hibernate could handle that in some fashion. Thanks, Derek View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4119261#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...