Performance Considerations

The following connection options can enhance driver performance. You can also enhance performance through efficient application design. Refer to "Designing ODBC Applications for Performance Optimization" in the DataDirect Connect for ODBC and Connect XE for ODBC Reference for details.

The option names found on the tabs of the driver Setup dialog box are the same as the connection string attribute names unless otherwise noted in parentheses. The connection string attribute name does not have spaces between the words. For example, the option name Application Using Threads is equivalent to the connection string attribute name ApplicationUsingThreads.

Application Using Threads (ApplicationUsingThreads): The driver coordinates concurrent database operations (operations from different threads) by acquiring locks. Although locking prevents errors in the driver, it also decreases performance. If your application does not make ODBC calls from different threads, the driver has no reason to coordinate operations. Disabling the Application Using Threads option prevents the driver from coordinating operations and improves performance for single-threaded applications.

NOTE: If you are using a multi-threaded application, you must enable the Application Using Threads option.

Cancel Detect Interval (CancelDetectInterval): If your application uses threads, it may allow canceling of long running queries (may issue synchronous SQLCancel calls). If your application does not issue synchronous SQLCancel calls, the driver can improve performance if Cancel Detect Interval is disabled (set to 0). In this case, the driver does not incur the overhead of periodically checking for SQLCancel. In the case where your application does issue synchronous SQLCancel calls, this option should be set to a value that specifies how often the driver checks to see if a long running query has been canceled.