Database updates can be rolled back either for the entire batch job or back to a specific checkpoint ID. The backout functionality is implemented in the MFDBUJCL IMS Database Utility JCL interface. You specify PARM='BBO' to activate batch backout. For example:
//BACKOUT EXEC PGM=MFDBUJCL,PARM='BBO'
If restarting from a checkpoint, the checkpoint ID is specified in the SYSIN DD, for example:
//SYSIN DD * CHKPT CHECK001 /*
Checkpoint options are listed in the table below.
| CHKPT Keyword | Behavior |
|---|---|
| LAST | Default. Restores to the point of the last successful checkpoint call. |
| ALL | Backs out all checkpoints. |
| checkpoint id | Restores to the checkpoint specified. This id is limited to eight characters. |