We've got our primary Oracle data warehouse running on *NIX, and a second one on Windows; both on our LAN. I've configured Heterogeneous Services / ODBC connections on the *dows database to various foreign databases (Informix, DB2, SQL Server).

Since I normally pull data from a fixed set of foreign tables (typically one schema per foreign database), I've got a schema per foreign database on the Windows database. For example, called VIEWDB2. In those schemas, I set up views on the foreign database, e.g.:
CREATE VIEW polqte AS SELECT * FROM ciopdba.polqte@DB2;
Similarly on the main database, I've got similarly-named schemas per foreign database that point to the views on the Windows database.
CREATE VIEW polqte AS SELECT * FROM viewdb2.polqte@Oracle_on_windows;
So on our main *NIX database (or on the Windows database), I can access, say, the DB2 database simply as:
SELECT * FROM viewdb2.polqte;

Sometimes though I'd like to write ad hoc queries against a foreign database. Is there any way of writing a query like this (from *NIX?)
SELECT * FROM ciopdba.polqte@db2@oracle_on_windows
? Or do we just log onto the Oracle_on_windows and write the ad hocs there?

Thank you.

ops$tkyte%ORA10GR2> create database link loopback@ora10gr2 connect to ops$tkyte identified by foobar using 'ora10gr2';

Database link created.

ops$tkyte%ORA10GR2> select * from dual@loopback@ora10gr2;

D
-
X

ops$tkyte%ORA10GR2> create database link loopback connect to ops$tkyte identified by foobar using 'ora10gr2';

Database link created.


ops$tkyte%ORA10GR2> select * from dual@loopback;
select * from dual@loopback
                   *
ERROR at line 1:
ORA-02085: database link LOOPBACK.REGRESS.RDBMS.DEV.US.ORACLE.COM connects to
ORA10GR2.REGRESS.RDBMS.DEV.US.ORACLE.COM