DataTypeCompatiabilty=80 OLE DB clients will connect using the SQL Server 2005 tabular data stream (TDS) version, rather than the TDS version. This means that for SQL Server 2008 and later data types, down-level conversion will be performed
by the server, rather than by SQL Server Native Client. It also means that the features available on the connection will be limited to the SQL Server 2005 feature set. Attempts to use new datatypes or features are detected as early as possible on API calls
and errors are returned to the calling application, rather than attempting to pass invalid requests to the server.