This error came up setting up a shared Data Source in SharePoint ?!
ORA-03134: Connections to this server version are no longer supported.
For a mix of older versions of Oracle databases. You need to pick the most appropriate driver.
Solution : Install a lower version of the Instant Client Libr. (just downgrade to the lowest level of Database version)
The good news:
It is possible to access an Oracle 8 Server with Oracle Instant Client 10 (see Metalink Note 207303.1).
The bad news: There is no Oracle Instant Client version 9. The product was introduced with Oracle 10g.
Connections to Oracle 9.0.1 databases are not supported.
Connecting with a 10.2 Instant Client to server version 126.96.36.199 or higher is supported.
or avoid the problem
Don’t use a shared Data Source but a Report Data Source