IGW8PNRU Routine for Batch Override

To prevent damage to a data set, DFSMStvs defers the decision whether to back out a specific record to an installation exit, the batch override exit. Transaction VSAM calls this optional exit when it backs out a unit of recovery (UR) that involves a data set that might have been impacted by the IDCAMS SHCDS PERMITNONRLSUPDATE command. The exit is called once for each affected undo log record for the data set.

The purpose of this exit is to return to DFSMStvs with an indication of whether or not the backout should be applied. The input is an undo log record (mapped by IGWUNLR) and a data set name. The output is a Boolean response of whether or not to do the backout, returned in register 15:

0 (zero) means do not back out this record.
4 means back out this record.

The exit is given control in the following environment:

INTERRUPTS enabled
STATE and KEY problem program state, key 8
ASC Mode P=H=S, RLS address space
AMODE, RMODE: No restrictions
LOCKS: None held
The exit is reentrant