I am new to ORACLE database and I have few basic doubts on ORACLE ODBC drivers. While creating a DSN I see Microsoft ODBC for ORACLE and ORACLE ODBC Driver drivers. What is the difference between these two drivers. And also I would like to know which is the latest available ORACLE ODBC driver and whether it is downward compatible.
The ones distributed by Oracle are made by Merrant Corporation, who worked with Oracle to ensure correct behavior. You should use their ODBC drivers, not the generic ones shipped with Windows. The Merrant OCBC drivers for Oracle are bundled with the Oracle Client. Database requests therefore hit your database using native TNS calls, and not <put adjective here> ODBC calls.