[web2py] can CAS provider use a different database to apps?

[Horus]

I desire to have multiple apps. one of them will be a CAS provider My 
questions are:

1. Can these app have different databases
   i.e db = DAL('postgres://user:password@localhost:5432/cas', 
migrate=True), db = DAL('postgres://user:password@localhost:5432/db1', 
migrate=True),   db = DAL('postgres://user:password@localhost:5432/db2', 
migrate=True)

2. How do I access these database tables  across applications?
    i.e how can app1 access CAS database OR how can app2 database to access 
app1 database



*Auth migration if disabled for all except CAS provider