Performance Considerations

The following connection options can enhance driver performance. You can also enhance performance through efficient application design. Refer to Chapter 5 “Designing ODBC Applications for Performance Optimization” in the DataDirect Connect Series for ODBC Reference for details.

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. In this case, the ApplicationUsingThreads attribute should be disabled (set to 0).

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 the CancelDetectInterval attribute 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 attribute should be set to a value that specifies how often the driver checks to see if a long running query has been canceled.