We currently have an Oracle 9i Client running on an HPUX Itanium platform and are looking at upgrading the Server from an Oracle 9i Windows 2000 Server to an Oracle 11g W2K3 Server.
Is an Oracle 9i Client compatible with an Oracle 11g Server?
Are there any problems with this configuration or is it recommended to upgrade the Oracle 9i Client to 11g as well?
It should, but the compatibility matrix that will tell you for sure is locked away inside Metalink. If you have a support contract you can access it here:
In the referenced Metalink article, it says the following about such connections:
"For connections between 10.2 (or higher) and 9.2 the 9.2 end MUST be at 9.2.0.4 or higher. Connections between 10.2 (or higher) and 9.2.0.1, 9.2.0.2 or 9.2.0.3 are not supported."
Cheers,
Opus