Hi,
ADO.NET only allow byte array for blob management.
It's very ineffective, if blob source or destination is a file. You convert data from unmanaged to managed, and then back from managed to unmanaged.
Why not extend the reader with GetBlob(int column, string fileName) and dbParameter with a new dbType "blobFile" and value = source file name.
With this mecanism blob would only exist in the unmanaged world and it would process very fast.
My two cents.
Remi