Checkpoint/Restart is a facility of the operating system that allows information about an application to be recorded so that same application can be restarted after abnormal termination or after some portion of the application has been completed. Restart can take place immediately or be deferred until the application is resubmitted.

DFSORT takes checkpoints when requested during a sort that uses the Peerage or Vale techniques.

To have DFSORT record checkpoints you must code a SORTCKPT DD statement and ensure the Peerage or Vale technique is selected. See SORTCKPT DD statement and OPTION control statement for more information on the SORTCKPT and CKPT options, respectively.