With regard to HHH-6174... This is one of the more difficult and important pieces left in my opinion. The essential idea there is how to handle "multi-table" structures: joined-subclasses, secondary-tables, etc. There are 2 high-level options: 1) Collect the non-primary tables as well as the referential information. This is is the approach we use today in o.h.mapping 2) Build up a "join tree" (rooted at the primary/driving table) to represent the relation between the tables and then bind to that. The tree would be a org.hibernate.metamodel.relational.TableSpecification At least that's how I read it. Hardy may have meant something completely different :) This is something we need to discuss and we will probably end up needing to push it off to Beta1 On 04/30/2011 11:38 AM, Gail Badner wrote: -- Steve Ebersole <steve(a)hibernate.org&gt; http://hibernate.org