Concatenating 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
//