[James0816]

I have a quick question...I am in the process of upgrading a machine running an Oracle database. The catch to this is that I have to have both the old version and the new version running at the same time (for transition and testing purposes). So here's the catch. After cloning the machine and upgrading the software application I now have two machines that have the same oracle database running on them (Oracle SID: TEST1).

I need to be able to access both databases while they are on the network. I believe I do this through the TNSNAMES.ORA file correct? But how do I do it since both databases have the same SID? I need to add another entry to the TNSNAMES files but I am confused with the SERVICE_NAME parameter and the first line (TEST1.MYDOMAIN.COM).

Here is the existing entry for the original database:

TEST1.MYDOMAIN.COM =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = TESTPC1)(PORT = 1521))
)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = TEST1)
)
)

Can someone help clear up the fuzzies for me?

Thx

[Littlefoot]

Simplified: TNSNAMES.ORA contains aliases to databases. It means that you can name a database the way you want. Important part of the story is what is behind the first "=" sign (description, address, host, service_name etc.). You can even have two, three or more aliases for the same database!

Now, you'd do that as follows:

TEST1_ON_OLD_MACHINE = 
(DESCRIPTION = ...
 (HOST = OLD_MACHINE) ...
)

TEST1_ON_NEW_MACHINE = 
(DESCRIPTION = ...
 (HOST = NEW_MACHINE) ...
)