We have a SQL Server 2014 running on a Windows Machine, with Oracle Client running. This client is used to Allow SQL server connect to remote Oracle Data sources.

This is the directory for which it's installed in: e:\app\user\product\11.2.0\client_1\

Due to an incompatibility issue, We need to upgrade/patch the Oracle client version to

Will this upgrade:

A) Create a second instance/directory of Oracle Client so that two different versions exist?

B) Solely overwrite/upgrade the existing version?

The reason I ask, On a completely different machine before, I had to upgrade from Version 10 to Version 11, which created seperete installation directories, and was a nightmare to have our prod support team update the Windows environment variables to have it point the TNS names to the newest version.


  • The fact that we have SQL server running on the machine is not entirely relevant. We have several linked Oracle Servers connected on the SQL server. One of them was upgraded to 19c, with our SQL server can no longer connect to, as the client needs to be upgraded from to Oracle Client is required to connect to remote Oracle instances, so if there is a better mechanism of connecting, I'd love to hear it. Commented Mar 10, 2023 at 3:11

1 Answer 1


Different versions are installed in different Oracle Homes, so I would expect the next installation to be say e:\app\user\product\11.2.0\client_2\

Are you sure that is the client version that you want to use? If you have an Oracle support contract, the knowledgebase article is Client / Server Interoperability Support Matrix for Different Oracle Versions (Doc ID 207303.1). If not, I am sure that you can find the matrix using Google. I'd be inclined to for something in the middle like 12.2.

You can set the %tns_admin% environment variable to point to the location of the sqlnet.ora and tnsnames.ora files. Personally I like to have them in a separate folder. SQL Server would probably need to be restarted to pick up the new environment variable, if you decided to go for that.

See https://oracle-base.com/articles/misc/oracle-instant-client-installation for an example.


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