DFSORT allows you to use user-written, installation-wide initialization and termination exit routines to perform a variety of functions, such as overriding the options currently in effect and collecting statistical data. For tuning purposes it is often advantageous to install these exits for the following reasons:

• These exits can be used for performance data gathering to help you understand the use of DFSORT at your site and make the appropriate tuning decisions based on this information.
• An initialization routine allows you to override the run-time values set for certain options, which enforces your decisions for those option values for all DFSORT applications at your site.