Thank you for the reply. But in that case I have to manage two reports. let me describe my scenario in detail.

I have two database. A and B

previously I have been using A for my reporting. Now I want to use B database and also need to preserve historic reports from A. My reports are large so if i go through manual approach I have to change all the queries (i.e A$tablename to B$tablename). So exploring if there is any alternative approach. Hoping for your reply.

Many thanks!!