Unit 4, Section 5: Checkpoint and restart

This video describes the program flow of checkpoint (CHKP) and restart (XRST). The CHKP and XRST DL/I service calls are frequently used together so that a failed batch or BMP or JBP program can be restarted and resume processing from near the point of failure.  In the absence of these calls, the application must be restarted from the beginning.