QSAM parallel input processing can be used to process two or more input data sets concurrently, such as sorting or merging several data sets at the same time.
A request for parallel input processing is indicated by including the address of a parallel data access block (PDAB) in the DCB exit list. The address must be on a fullword boundary with the first byte of the entry containing X'12' or, if it is the last entry, X'92'. For more information about parallel input processing see PDAB—Parallel Input Processing (QSAM Only).