Given a database table with a large number of columns, I'd like to have 2 java classes for this table...

Class A would only map to a few of the table's columns and will be used as a "lightweight" version of the table, i.e. lower serialization penalty.

Class B would extend class A and refer to all the fields. Only instances of class B would ever be created/saved.

My initial attempt of mapping both classes to the same table (each with a regular <class> mapping) produced a problem. When trying to get(...) an instance of class B, I'd get back class A instead even though class B's class object was passed in. I cannot modify the table, and none of the Hibernate inheritance strategies I read about seem to apply... is what I want to do possible in Hibernate 2.x+?

Thanks ahead of time for any thoughts.

i wanted to do a similar thing, but hibernate is not sophisticated enough yet to do that... ended up having to redesign stuff >:(

Thats why there is a pattern for exactly this in the Wiki for 2 years...

So others don't have to dig around for it in the Wiki:

Lightweight Class