Oh!  I'm sorry... let me begin from scratch...
I've got a system working with an Oracle DB.  There are also distributed systems that work with Postgres Dbs.  I need to use queues and send messages between them.  As I've learnt, they are supposed to be comunicating via ODBC.  Is there any kind of user authentication other than the permissions granted by de DBA?  What does it use to perform the authentication? 
Is there any documentation I can read to know the technical procedures a message follows since it has been staged in a queue, and until it is dequeued?