Use the following keywords to process VSAM data sets once they have been retrieved. Use these parameters to process existing VSAM data sets, not to allocate new VSAM data sets. For information about the JCL parameters used to allocate a new VSAM data set see Creating VSAM Data Sets with JCL.

AMP is only used with VSAM data sets. The AMP parameter takes effect when the data set defined by the DD statement is opened.

Note: This is not supported by RLS.

DDNAME lets you postpone defining a data set until later in the job step.

DISP =(SHR|OLD[,PASS]) describes the status of a data set, and tells the system what to do with the data set after the step or job ends.

DSNAME specifies the name of a data set.

DUMMY specifies that no disposition processing is to be performed on the data set. It also specifies that no device or external storage space is to be allocated to the data set.

DYNAM increases by one the control value for dynamically allocated resources held for reuse.

FREE specifies when the system is to deallocate resources for the data set.

PROTECT tells RACF to protect the data set.

UNIT =(device number|type|group,p|unitcount) places the data set on a specific device or a group of devices.

VOLUME =(PRIVATE|SER) identifies the volume on which a data set will reside.

With SMS, you do not need the AMP, UNIT, and VOLUMES parameters to retrieve an existing VSAM data set. With SMS, you can use the DISP subparameters MOD, NEW, CATLG, KEEP, PASS, and DELETE for VSAM data sets.

Certain JCL keywords should either not be used, or used only with caution when processing VSAM data sets. See the VSAM data set topic in z/OS MVS JCL User's Guide for a list of these keywords. Additional descriptions of these keywords also appear in z/OS MVS JCL Reference.