Jcl
Introduction to JCL Jcl coding sheet JOB Statement Exec statement DD Statement Concatenating Datasets Referback in JCL Special DD statements Utility Programs Utility program IEBGENER Utility programs IEBCOPY and IEBCOMPR DFSort DFSort reformat dataset DFSort INCLUDE OMIT COND Procedures generation data group (GDG) JCL quick study JCL Interview questionsConcatenating Datasets
We can retrieve two or more data sets and process them successively as a single sequential data set. This is called sequential concatenation. A sequential concatenation can include sequential data sets, PDS members, PDSE members.
Rules for Concatenation:
- DDname should be coded for the first DD statement only.
- The sequence in which the datasets are coded is the sequence in which they are concatenated.
- We can concatenate PDS, PDS members and PS datasets, but not VSAM datasets. Cannot concatenate PDS entirely with sequential datasets.
- All datasets must have the same RECFM.
- The LRECL must also be the same for fixed-length records.
- LRECL need not be same for variable-length records as long as you place the dataset with the longest LRECL on the first DD statement.
- BLKSIZE need not be same .
- You can concatenate as many as 114 PDS as PDSs. No concatenation limit on the PDS members or on PS.
- Datasets can reside on different devices
- If dummy dataset is coded, any preceding dataset coded are not processed.
//PROGPUB JOB NOTIFY=&SYSUID,MSGCLASS=A,MSGLEVEL=2
//STEP1 EXEC PGM=PROGRAM1
//INPUT DD DSN=PROGPUB.FLATFILE.INPUT1,DISP=SHR
// DD DSN=PROGPUB.FLATFILE.INPUT2,DISP=SHR
// DD DSN=PROGPUB.FLATFILE.INPUT3,DISP=SHR
//
Example with dummy dataset
//* PROGPUB.FLATFILE.INPUT3 File is not processed
//PROGPUB JOB NOTIFY=&SYSUID,MSGCLASS=A,MSGLEVEL=2
//STEP1 EXEC PGM=PROGRAM1
//INPUT DD DSN=PROGPUB.FLATFILE.INPUT1,DISP=SHR
// DD DSN=PROGPUB.FLATFILE.INPUT2,DISP=SHR
// DD DSN=DUMMY
// DD DSN=PROGPUB.FLATFILE.INPUT3,DISP=SHR
//