GDG Processing
Problem Description
Write JCL to create a new generation of a GDG and also reference the previous generation.
Expected Output
Creates (+1) and reads (0) generation
Hints
Use relative generation numbers (+1, 0, -1).
Solution
//GDGJOB JOB (ACCT),CLASS=A
//*
//* READ CURRENT GENERATION (0)
//STEP1 EXEC PGM=READPGM
//INPUT DD DSN=MY.GDG.FILE(0),DISP=SHR
//SYSPRINT DD SYSOUT=*
//*
//* CREATE NEW GENERATION (+1)
//STEP2 EXEC PGM=WRITEPGM
//OUTPUT DD DSN=MY.GDG.FILE(+1),
// DISP=(NEW,CATLG,DELETE),
// SPACE=(CYL,(10,5)),
// DCB=(RECFM=FB,LRECL=80)
//SYSPRINT DD SYSOUT=*
//
Explanation:
GDG(0) is current, (+1) creates new, (-1) is previous. LIMIT controls versions.