Oracle Database Administration: The Essential Refe

Open DataBase Connectivity

The Open DataBase Connectivity (ODBC) is actually an Application Programming Interface (API) specification developed by Microsoft. Because ODBC provides a standard interface to both the application program and the backend server, it allows any ODBC-compliant application to connect to any ODBC-compliant database. ODBC has been implemented for Oracle in two ways:

Native mode ODBC

The ODBC driver duplicates the functionality of SQL*Net, so a client running an ODBC driver can connect to a server running SQL*Net without actually running SQL*Net software on the client machine. Thus, the ODBC driver is able to emulate SQL*Net. This capability is not provided by Oracle, but is implemented by other vendors of ODBC drivers.

SQL*Net integrated

The ODBC driver provides an interface to SQL*Net that, in turn, actually carries the data to the target node. This is the more common implementation of ODBC, where the ODBC layer actually sits on top of SQL*Net.

Because many applications have been built to interface with ODBC, this technology allows a wide range of applications to connect to an Oracle database without the need to provide a native SQL*Net interface. However, because ODBC relies on SQL*Net for its underlying transport, communications using ODBC are typically less efficient than native SQL*Net. In addition, some Oracle functionality is not fully supported by ODBC drivers. This lack of functionality is easily mistaken for an application problem, and may be difficult ...