DSENQSHR parameter

Parameter type: Keyword, optional

Purpose: Indicates how the system will treat changes in data set disposition between job steps.

When a step includes a DD with OLD, NEW or MOD on the DISP (disposition) keyword, and a later step requests the same data set as SHR, this parameter controls whether the system can change the serialization on the data set to shared control, allowing other jobs to also share that data set.

Note: Only changes to SHR are honored. In addition, if the data set is requested as OLD or MOD again later in the job, exclusive control will remain until only SHR requests remain. This ensures that all updates to the data set are complete before allowing other jobs to request the data.