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JCL DD Statement

Intermediate 🕑 25 min read 👁 1 views

DD Statement Overview

The DD (Data Definition) statement defines the data sets used by a program. It's the most complex JCL statement with many parameters.

DD Statement Syntax

//ddname DD parameters

Key DD Parameters

Parameter	Description
DSN/DSNAME	Data set name
DISP	Data set disposition
UNIT	Device type
VOL	Volume serial
SPACE	Space allocation
DCB	Data control block parameters
SYSOUT	System output class

DISP Parameter

DISP=(status,normal-end,abnormal-end)

Status values:

NEW - Create new data set
OLD - Exclusive access to existing
SHR - Shared access to existing
MOD - Add to end of existing or create

Disposition values:

DELETE - Delete data set
KEEP - Keep data set
CATLG - Catalog data set
UNCATLG - Uncatalog data set
PASS - Pass to next step

SPACE Parameter

SPACE=(unit,(primary,secondary,directory),RLSE)

TRK - Tracks
CYL - Cylinders
blksize - Block size

DCB Parameter

DCB=(RECFM=FB,LRECL=80,BLKSIZE=27920)

RECFM - Record format (F, FB, V, VB)
LRECL - Logical record length
BLKSIZE - Block size

Code Example

//INPUT    DD DSN=MY.INPUT.FILE,DISP=SHR
//*
//OUTPUT   DD DSN=MY.OUTPUT.FILE,
//            DISP=(NEW,CATLG,DELETE),
//            UNIT=SYSDA,
//            SPACE=(CYL,(10,5),RLSE),
//            DCB=(RECFM=FB,LRECL=100,BLKSIZE=0)
//*
//* TEMPORARY DATA SET
//TEMP     DD DSN=&&TEMPFILE,
//            DISP=(NEW,PASS),
//            SPACE=(TRK,(5,1))
//*
//* SYSOUT - PRINT OUTPUT
//SYSPRINT DD SYSOUT=*
//REPORT   DD SYSOUT=A
//*
//* INSTREAM DATA
//SYSIN    DD *
INPUT DATA LINE 1
INPUT DATA LINE 2
/*
//*
//* CONCATENATED DATA SETS
//INPUT    DD DSN=FILE1,DISP=SHR
//         DD DSN=FILE2,DISP=SHR
//         DD DSN=FILE3,DISP=SHR
//*
//* GDG - GENERATION DATA GROUP
//GDGOUT   DD DSN=MY.GDG.FILE(+1),
//            DISP=(NEW,CATLG,DELETE)
//GDGIN    DD DSN=MY.GDG.FILE(0),DISP=SHR
//*
//* DUMMY DD
//OPTIONAL DD DUMMY
//*
//* REFERBACK
//FILE2    DD DSN=*.STEP01.OUTPUT,DISP=SHR