On Jul 8, 11:30 am, Chuck <chuckh1958_nos...@gmail.com> wrote:

I wonder if a simple change in the TNSNAMES.ORA is sufficient to
accomplish what needs to be done?  Assume that TNSNAMES.ORA contains
the following to allow a client to connect to the production database
instance:
PROD =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = PROD-SERVER)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = PROD)
    )
  )

Also, assume that you need a TNSNAMES.ORA entry to connect to the test
database instance on the test server that looks like this:
TEST =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = TEST-SERVER)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = TEST)
    )
  )

On the client computer that should only connect to the test database
instance when using the same connection string as would be used on
another client when connecting to the production server, the
TNSNAMES.ORA entry might look like this:
PROD =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = TEST-SERVER)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = TEST)
    )
  )

In the above, when the client requests to connect to "PROD", it
actually connects to a database instance named "TEST" on a different
server.  I recently used the above approach to test a newer version of
an ERP package, and a number of custom developed applications with
hard coded connection strings targeting the data of the ERP system.  A
similar approach may work for your needs.

I believe that DBID has a special meaning, which is causing some
concern from people responding in this thread, when you state you want
two databases to have the same DBID.

Charles Hooper
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc.