原生OLE DB和ADO.NET之间的速度差异

I'm looking for suggestions as well as any benchmarks or observations people have. We are looking to rewrite our data access layer and are trying to decide between native C++ OLEDB or ADO.NET for connecting with databases. Currently we are specifically targeting Oracle which would mean we would use the Oracle OLE DB provider and the ODP.NET. I'm looking for suggestions as well as any benc