They are separate databases connections, and almost always totally different database servers, and often different databases completely.

The only way to do this, is to set up a linked server, expose all of the tables to want to deal with through the linked server, then import those tables through Integration Studio.

Oh, and the performance is horrific, because the linked server has to query the different databases to get all of their data, then join the tables in its own memory.

I have *had* to do this on a project, and never in my life would I recommend it.

J.Ja