I am trying to map a legacy data-model that, due to SQLServer2000 table size restrictions, splits a single entity into multiple tables with a shared key. The entity in question is also the child node of a polymorphic hierarchy (i.e Employee where Employee extends Person), which is mapped as a joined-subclass. It looks like I should be using the <join> element to bring in all the data from the various tables that make up the entity (think EMPLOYEE_ADDRESS, EMPLOYEE_NAME, etc..., but the these tables should not be mapped to the root class), but the Hibernate3.1 DTD does not allow a <join> inside a <joined-subclass>. Is there any way to fix this? Should I just map it using a <one-to-one> even though the tables do not repesent stand-alone business objects? Any help would be greatly appreciated!