Hi Hassan,
Do you really need alias of table B? What are you join on, between B and B'?
You said that you're training users so they know what to bring and what not to in one query. I'm assuming you're worried about them bringing in objects from multiple contexts. Correct?
I've used Business Layer Views (BLV) to do that, I don't know if that's the way to do it. Whenever I try to search about BLV, I see blogs with same old garbage then BLVs are replacement for Derived Universes...
We had a Universe with 10 contexts, what I did is, I created one Business Layer View for each Context, BLV 1 would include all the objects that we can pull and be assured that the SQL generated will be using Context 1 as no incompatible object in included in that BLV. So, I created those 10 BLVs, now I asked the users to select a BLV before creating a query, so they don't make an error of selecting objects from multiple queries even by mistake. Make sense?
Thanks,
Mahboob Mohammed