Hi. In dealing with a performance issue on objects attached to a document, I came up with an approach to create a subclass of BaseObject that has its own Hibernate mapping, and can include other full-class Java objects as children, etc. This works pretty well but requires some hacking in that it doesn' t seem like XWiki will load a subclass of BaseObject directly, so I have to force this reloading when I access the object. The main advantage is this allows me to have properties that are loaded in one SQL roundtrip, as opposed to one SQL query per actual object instance, which is the best that seems possible with the built- in custom mappings. I'm wondering if there it would make sense to incorporate this kind of custom subclassing into the XWiki base code. I think it could be done without a lot of work (when the store reads the object's class, if it is a subclass of BaseObject it reloads that particular object using the appropriate mappings). For our own project we can probably do this with local patches, but it seems like it might be useful to others. Any thoughts?