Easytrieve Customer Master Update Projects

Change Transaction File Layout

1
2
3
4
5
6
7
8
9
10
11
FILE CHGTRAN
   ACTION-CODE   1 A
   CUST-ID       9 NUM
   CUST-NAME    30 A
   ADDR-LINE1   30 A
   ADDR-LINE2   30 A
   CITY         20 A
   STATE-CODE    2 A
   ZIP-CODE      9 A
   CHG-DATE      8 NUM
   CHG-USER      8 A

ACTION-CODE values: A add, C change, D delete—document exact codes in header comment. CUST-ID is match key to master. Change file may carry full record image on change or partial fields with overlay semantics—shop standard must define whether blank ADDR-LINE2 means clear field or leave unchanged.

Action Code Processing

Merge-Apply Pattern (Two-File Match)

Classic pattern: SORT master and changes by CUST-ID. Single pass merge: read master and change in lockstep comparing keys. When keys equal, apply change to master buffer and WRITE new master row. When change key lower, process add. When master key lower, copy master unchanged. Requires careful EOF handling on both files in JOB or two-step design with indexed lookup.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
JOB INPUT CHGTRAN
   PERFORM VALIDATE-CHANGE
   IF W-ERROR-FLAG EQ 'Y'
      PERFORM WRITE-EXCEPTION
      GOTO JOB
   END-IF
   IF ACTION-CODE EQ 'A'
      PERFORM PROCESS-ADD
   ELSE IF ACTION-CODE EQ 'C'
      PERFORM PROCESS-CHANGE
   ELSE IF ACTION-CODE EQ 'D'
      PERFORM PROCESS-DELETE
   END-IF
   W-APPLY-CNT = W-APPLY-CNT + 1

Alternative: random READ master by CUST-ID for each change when master is VSAM KSDS—simpler logic, heavier I/O. Batch rewrite sequential generation suits nightly volume with full backup.

Validation Module

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
VALIDATE-CHANGE. PROC
   W-ERROR-FLAG = 'N'
   IF CUST-ID EQ ZEROES
      W-ERROR-FLAG = 'Y'
      W-ERROR-MSG  = 'MISSING CUST ID'
   END-IF
   IF ACTION-CODE EQ 'A' AND CUST-NAME EQ SPACES
      W-ERROR-FLAG = 'Y'
      W-ERROR-MSG  = 'NAME REQUIRED ON ADD'
   END-IF
   IF STATE-CODE NE SPACES
      SEARCH STATETAB WITH STATE-CODE GIVING ST-NAME
      IF NOT STATETAB
         W-ERROR-FLAG = 'Y'
         W-ERROR-MSG  = 'INVALID STATE'
      END-IF
   END-IF
END-PROC

Audit Trail Output

Write AUDIT-FILE row on every applied change: CUST-ID, ACTION-CODE, CHG-DATE, CHG-USER, key fields before and after when policy requires field-level history. Audit file append-only GDG supports compliance queries. Separate from exception file which captures rejected transactions only.

Delete Versus Deactivate

Regulatory and AR policy often forbids physical delete. PROCESS-DELETE sets INACTIVE-FLAG Y and INACTIVE-DATE rather than omitting record from new master. Invoice jobs filter IF INACTIVE-FLAG NE Y. Hard delete reserved for test environments or GDPR programs with legal approval and documented retention destruction.

Control Totals and Swap Discipline

• W-READ-CNT change transactions read.
• W-APPLY-CNT successfully applied.
• W-EXCEPT-CNT rejected validations.
• W-MASTER-OUT-CNT records on new master generation.
• Compare W-MASTER-OUT-CNT to prior master count plus adds minus deletes within tolerance.

Operations backs up current master before swap. New generation renamed or repro loaded to VSAM only after control report sign-off. Rollback plan restores backup generation if downstream billing job fails.

Sample JCL

1
2
3
4
5
6
7
8
//CUSTUPD  EXEC PGM=EZTPA00,REGION=0M
//SYSPRINT DD SYSOUT=*
//SYSIN    DD DSN=MDM.LIB(EZTCUSTU),DISP=SHR
//OLDMAST  DD DSN=CUST.MASTER.CURRENT,DISP=SHR
//CHGTRAN  DD DSN=CUST.CHANGES(+1),DISP=SHR
//NEWMAST  DD DSN=CUST.MASTER.NEW(+1),DISP=(,CATLG,DELETE)
//AUDIT    DD DSN=CUST.AUDIT(+1),DISP=(,CATLG,DELETE)
//EXCEPT   DD DSN=CUST.CHNG.EXCEPT(+1),DISP=(,CATLG,DELETE)

Integration With Downstream Jobs

Scheduler dependency: CUSTUPD completes before INVGEN and STMTGEN. Master refresh late in window may delay billing—monitor W-EXCEPT-CNT threshold that blocks swap when too many errors indicate bad vendor feed. Staged validation environment applies same job against copy master before production feed.

Explain It Like I'm Five

Customer master update is like keeping the class phone book current. Friends bring notes saying add this person, fix that address, or remove someone who moved away. Easytrieve checks each note makes sense, updates the phone book, and keeps a diary of every change. If a note is messy, it goes on the ask-the-teacher list instead of ruining the whole book.

Exercises

1. Define CHGTRAN and VALIDATE-CHANGE. PROC with three rules.
2. Document action codes A, C, D behavior in program header.
3. Design audit row fields for one address change.
4. List four control counts for master swap sign-off.
5. Compare VSAM in-place update versus sequential rewrite trade-offs.