Using the Program-I/O report

Using the Program-I/O report, you can correlate IWAIT time with a specific PCB and data set. This allows you to identify databases that are causing a relatively large number of IWAITs.

Because IWAITS are identified by PCB and data set names, you might be able to trace the large number of IWAITs back to a particular application program. If you can, give the application program special attention when tuning for performance. The DL/I-Call-Summary report, described in the following topic, helps you identify specific DL/I calls in an application program that are causing a large number of IWAITs.