Datacom considerations

QUICKSTART programs running under Datacom can run in Single User mode or under the Multi-User Facility (MUF). If running in Single User mode, perform Logging. If an ABEND occurs, run the Backout Utility to backout Database updates to the last DBMS “COMMIT”.

URT's should specify TXBKOUT=YES. Each URT also needs UPDATE=YES for the QUICKSTART Checkpoint Control Table.

Datacom maintains application program positioning after a Database “COMMIT” (“LOGCP” or “COMIT”) is issued. Therefore, there is no need to test the value of CKPT-TAKEN-FLAG after invoking CKPT-RTN.

There are some additional non save-area fields that need to be included into the application to control the Calls to the QUICKSTART Checkpoint Control Table. These fields, shown below, are contained within the SAMPLIB member DCOMCOB.

01 COMMIT-REQ.
       05 COMMIT-CMD PIC X(5) VALUE 'LOGCP'.
       05 FILLER PIC X(8) VALUE LOW-VALUES.
       05 COMMIT-RC PIC XX.
       05 FILLER PIC X(256) VALUE LOW-VALUES.
     *
      01 CKPT-REQ.
       05 CKPT-CMD PIC X(5).
       05 CKPT-TBL PIC XXX.
       05 CKPT-KEY PIC X(5).
       05 CKPT-RC PIC XX.
       05 FILLER PIC X(61) VALUE LOW-VALUES.
       05 CKPT-FULLKEY PIC X(20).
      01 CKPT-ELMLST PIC X(23).
     *
      01 CKPT-UIB PIC X(32).

Datacom considerations

QUICKSTART for MVS 3.4

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