Parameter type

Keyword, optional–use this parameter only with SMS.

Without SMS, use the RKP subparameter of the DCB parameter described in DCB subparameters.

Purpose

Use the KEYOFF parameter to specify the key offset, the position of the first byte of the record key in each logical record of a new VSAM data set. The first byte of a logical record is position 0.

If SMS is not installed or is not active, the system syntax checks and then ignores the KEYOFF parameter.

Code the KEYOFF parameter only for a VSAM key-sequenced data set (RECORG=KS).

Code the KEYOFF parameter when you want to (1) specify a key offset for the data set or (2) override the key offset defined in the data class of the data set.

References

See z/OS DFSMS Using Data Sets for information on VSAM key-sequenced data sets.