I'm working on "object spanning database transactions". If you look at the L'ane code, each class is a little island. I hope this change will increase the speed of the system and will allow cross-object db transactions.
Yesterday I decided to take a look at the UnifiedPOS (on what JavaPOS and OLE for POS are based) docs. Ick, like a thousand pages of UML diagrams. Needless to say, I didn't get very far there. (this research is for the event model)
