Additional ESDS considerations

When a record is added to a VSAM ESDS by a batch job, CICS® VR undo logging writes a before-image log record with the RBA of the record that was added to the undo log stream. Therefore, during batch backout processing, CICS VR locates any records that were added to the ESDS by the batch job step.

However, because ESDS records are written sequentially, CICS VR cannot physically delete them. Instead, these records that were added to ESDSs must be logically marked-for-deletion. The method used to logically mark ESDS records for deletion varies between environments. Therefore, CICS VR allows you to specify a CICS VR batch backout ESDS delete exit in a batch backout job.

The CICS VR batch backout ESDS delete exit is passed the ESDS record that was added by the batch job step. The exit can then mark the record for deletion according to your environment's standards. The exit then passes the marked-for-deletion ESDS record back to CICS VR, along with an action code indicating the next step for CICS VR to take; terminate, ignore, or replace the ESDS record with the marked-for-deletion record and continue. For further information about creating the exit, see the CICS VR Implementation Guide and Reference.

You must add the following command to the input command area, after the DWWIN DD * statement, to all CICS VR batch backout jobs that attempt to remove one or more records that were added to a VSAM ESDS.

DEFEXIT ESDSDELETE(batch backout ESDS delete exit program)

batch backout ESDS delete exit program is the name of the CICS VR batch backout ESDS delete exit program.

If the exit program is not in the link list, the exit program must reside in a data set that is defined to the JOBLIB, STEPLIB, or DWWLOAD ddname. You also can keep the exit program in your CICS VR load library.

If you have configured CICS VR to start batch backout automatically when a batch job encounters an abend, make the ESDS delete exit changes mentioned earlier to the batch backout JCL skeleton DWWBAFJS.