Hi Yakov;
FWIW:
1) OLE-DB, ADO.Net & ODBC are Middleware.
2) PB is ANSI result based which is handled natively in SNC
3) In the use of Middleware, PB's ANSI based DML commands are converted to Middleware syntax on the way to the DBMS.
4) DBMS like SS or ASE return ANSI result set format. In the case of Middleware, the RS returned is in Middleware format - which in turn gets converted back to an ANSI RS format for PB. The overhead of this RS conversation varys by MW implementation.
5) SNC supports special RS handling like MARS as an example.
6) SNC supports RPC DBMS access.
HTH
Regards ... Chris