If I have multiple Oracle clients installed on a given workstation (i.e. Oracle 9 and Oracle 10), how do I specify which one is used by ADO? Is there a way to swap between the two clients?
I am currently using the Oracle Provide - oraoledb, not the Microsoft provider.
The Microsoft provider depends upon the current Oracle Home (environment path). Now you can change this through the Oracle Home selector but the Microsoft provider does not support the ability to change the path programmatically.
The first oracle home which is specified in the PATH environment variable is used. Be aware that this is user specific and if you change it in a process, it's local to that process.
In general you shouldn't switch homes inside software, though simply use the latest one. Unless you're targeting 8i, the 10g client can connect to 9i without problems.
Apparently, I asked a trick question...although you can indeed use multiple Oracle Homes, the Oraoledb driver does not support multiple homes. In fact, since the OraOLEDB component is based on COM, it can only be installed correctly to one location at a time...