There is a concept of Database link?
Oracle Heterogeneous service (Trasparent gateway for ODBC) can create a link
to odbc database and the yuo can query 2 table across 2 different DB.
Select products.* , customer.name
from products, customer@MSAccessdb
where products.id=customer.id
P.S.
contrib/dblink can link external odbc/jdbc source.
