If you want to use the storage tuning user exit to collect storage usage information instead of using RPTSTG(ON), you can use a storage tuning user exit that always requests that Language Environment collect storage tuning information.

When running on non-CICS, the behavior of the storage tuning user exit could be as follows:

• At the region initialization call, the storage tuning user exit opens a file for output. The storage tuning user exit will write the Language Environment storage information to the file at enclave termination.
• At the enclave initialization call, the storage tuning user exit always requests Language Environment to collect storage information.
• At the enclave termination call, the storage tuning user exit can make a call to the system to determine the load module name of the main program by using CSVQUERY, and then it can write a record to a file which includes the load module name and the storage usage information. On the CSVQUERY call, you use the address of the main program that is passed to the storage tuning user exit as input in the INADDR parameter, and use the OUTEPNM parameter to get the load module name.
• At the region termination call, the storage tuning user exit closes the file it opened.

When running on CICS®, the behavior of the storage tuning user exit could be as follows:

• At the region initialization call, the storage tuning user exit returns immediately.
• At the new load module call, the storage tuning user exit always enables the use of the storage tuning user exit for the load module.
• At the enclave initialization call, the storage tuning user exit always requests Language Environment to collect storage information.
• At the enclave termination call, the storage tuning user exit gets the name of the module, and then writes a record to a file where the record includes the load module name and the storage usage information.
• At the region termination call, the storage tuning user exit returns immediately.

After the file is closed, the data in the file can be analyzed. Once the data has been analyzed, you might decide to alter your runtime option defaults, or provide a CEEUOPT to certain modules, or use the storage tuning user exit to provide storage values.