Call Level Interface Guide and Reference

ODBC Driver Manager Tracing

It is useful to understand the difference between the ODBC trace provided by the ODBC Driver Manager and the DB2 CLI/ODBC driver (IBM ODBC Driver Tracing).

Output file formats are different. The distinction is that the ODBC trace will show the calls made by the application to the Driver Manager. The DB2 CLI trace shows the calls received from the ODBC Driver manager.

The ODBC driver manager may map application function calls to either different functions, different arguments or may delay the call.

One or more of the following may apply:

• Applications written using ODBC 2.0 functions that have been replaced in ODBC 3.0, will have the old functions mapped to the new ones by the ODBC Driver Manager.
• Some function arguments may have their values mapped from ODBC 2.0 values to equivalent ODBC 3.0 values.
• The Microsoft cursor library will map calls such SQLExtendedFetch() to multiple calls to fetch, and other supporting functions.

For these reasons you may need to enable and compare the output of both traces to get a clear picture of what is happening.

For more information, refer to the Microsoft ODBC 3.0 Software Development Kit and Programmer's Reference.