Multiple version of Oracle

[Mushy]

Hello All,

I have multipe version of Oracle client installed.

How to I ensure that it works for latest version of the oracle client and the old version is not refreed at all?

Thanks,

Mushy

[gwootton · Accepted solution]

I think which client is used is driven by your ORACLE_ environment variables.

[Sajid01]

Further to what @gwootton  has said change the port numbers in the configuration files for the clients and installation. 
Keep the default port (1521) for current installation and a different port for the older installation.
tnsname.ora etc should have the  port number for the installation that is desired to be used.