Merging previously sorted data sets

You can use DFSORT's MERGE operator to create merged output data sets. A single MERGE operator can be used to merge up to 50 input data sets which were previously sorted by the same fields in the same locations. MERGE can create one output data set or up to 10 identical output data sets. Using INCLUDE or OMIT statements, you can select a subset of the input records. Using INREC or OUTREC statements, you can rearrange the fields of the input records. Using OUTFIL statements, you can create any number of output data sets with different subsets of records or arrangements of fields.

You can use up to 10 FROM operands to specify up to 50 input data sets. You must specify a USING data set to specify a DFSORT MERGE statement that tells MERGE the fields your input data sets are already sorted on. You can use various other DFSORT statements as well; see z/OS DFSORT Application Programming Guide for details.

Suppose you have two input data sets previously sorted by Branch Number as follows:

0003 Sacramento
0005 Palo Alto
0008 Morgan Hill

0002 Los Angeles
0006 Modesto
0009 San Jose

//MRG EXEC PGM=ICETOOL
//TOOLMSG DD SYSOUT=*
//DFSMSG DD SYSOUT=*
//IN1 DD DSN=INPUT.FILE1,DISP=SHR
//IN2 DD DSN=INPUT.FILE2,DISP=SHR
//OUT DD DSN=OUTPUT.FILE,DISP=(NEW,CATLG,DELETE),
//  UNIT=SYSDA,SPACE=(CYL,(5,5))
//TOOLIN DD *
   MERGE FROM(IN1,IN2) TO(OUT) USING(CTL1)
/*
//CTL1CNTL DD *
   MERGE FIELDS=(1,4,ZD,A)
/*

0002 Los Angeles    
0003 Sacramento     
0005 Palo Alto      
0006 Modesto        
0008 Morgan Hill    
0009 San Jose