Example of compress operations

The following example compresses a selected partitioned data set.

//JOB1     JOB  accounting information,REGION=nnnnK
//STEP1    EXEC PGM=ADRDSSU
//SYSPRINT DD   SYSOUT=A
//SYSIN    DD   *
 COMPRESS              -
   DYNAM(338000)       /* DYNAM ALLOC VOL 338000        */ -
   EXCLUDE(SYS1.**)    /* EXCL 'SYS1....' DATA SETS     */ -
                       /* IF THEY MEET THIS CRITERION   */ -
   BY((DSCHA EQ 0))    /* DATA SET WAS BACKED UP        */
 /*

Compress partitioned data sets on volume 338000 if:

They are not system data sets (EXCLUDE(SYS1.**)), and
They have not been updated (DSCHA EQ 0) since the last time they were backed up (dumped). This ensures that the data set can be recovered if the system fails while the compress operation is running.