Hi Rajesh,
B1 SDK will not give you a direct connection to the underlying database, meaning that, if you want to use ADO.NET or so, you will need to keep somewhere, in whatever form, the credentials to connect.
Using Recordset objects are much faster than what it was in previous versions... And with the "correct" architecture, you can at the full speed of the RDBMS without the constraints of B1.
Regards;
Eric