I am using SSRS to report against an Oracle database source directly. For a while I was getting the following error.
Attempt to load Oracle client libraries threw BadImageFormatException. This problem will occur when running in 64 bit mode with the 32 bit Oracle client components installed.
Apparently there is a difference between the Oracle Client install package and the Oracle Data Access Components. Probably just a bonehead mistake on my part.
Here’s the link to the actual installable you need to access Oracle databases thru Sharepoint 2010 and SSRS. You do need the 64 bit package on the server that hosts Reporting Services.
I understand you will need the 32 bit package for Visual Studio.