User269602965 posted
In similar environment
I did not use System.Data.OracleClient and instead used Oracle.DataAccess.Client (ODP.NET/ODAC)
You can get the latest version of ODP.NET 32-bit since your apps are 32-bit, eventhough OS and IIS are 64-bit.
During the installation select CLIENT INSTALL (not the database install).
The GAC will be populated with Oracle Data Access, several versions supporting 10g/11g
Read the ODAC install guide for the minor changes required in web.config and REFERENCES.
Sometimes, I have to make minor changes in code behind page if I am migrating from System.Data.OracleClient to Oracle.DataAccess.Client,
and Intellitype has always fixed the minor wording changes for me.
http://www.oracle.com/pls/db112/portal.portal_db?selected=5&frame=#.net_and_windows_application_development
And although maybe a bad practice in large corporations with many versions of databases, app plaforms, etc.
I get the exact version of the ODAC dll that I need for my Oracle database (for ASP.NET 3.5 that would be in the oracle home/odp.net/bin 2.0 folder)
put that in my application /BIN folder and make a local reference to it.
But I operate in small business with one or a few databases and infrequent database major upgrades,
so micromanaging ODAC versions within app code is not a major headache for me.