Background: I'm developing an ASP.NET web application that will developed in Visual Studio 2010 on Windows XP 32 bit OS (company standard, cannot change). The target server is a Windows 2008 Server 64 bit (IIS 7). The application will be referencing an unmanaged dll (Oracle ODP.NET, 11.2) that has both 32 bit and 64 bit versions.
Question: In general, what is the best approach to develop a .NET application that references an unmanaged dll that has both 32 bit and 64 bit versions from a 32 bit OS development environment that deploys to a 64 OS? One solution mentioned was to switch to 32 bit mode in IIS, but I would like to keep the performance gain from the 64 bit driver.