DFSORT - SPLIT,SPLITT1R And SPLITBY - Difference

These are some basic differences. Reference is IBM.

SPLIT = It splits input records evenly into output files

Example:

OPTION COPY
  OUTFIL FNAMES=(OUTPUT1,OUTPUT2),SPLIT

With 17 input records, the results produced for OUTPUT1 are:

Record 01
Record 03
Record 05
Record 07
Record 09
Record 11
Record 13
Record 15
Record 17

The results produced for OUTPUT2 are:

Record 02
Record 04
Record 06
Record 08
Record 10
Record 12
Record 14
Record 16

SPLITBY = n == >It splits records 'n' at a time to output datasets

Example:

 OPTION COPY
  OUTFIL FNAMES=(OUT1,OUT2,OUT3),SPLITBY=4

With 17 input records, the results produced for OUT1 are:
Record 01
Record 02
Record 03
Record 04
Record 13
Record 14
Record 15
Record 16

The results produced for OUT2 are:
Record 05
Record 06
Record 07
Record 08
Record 17

The results produced for OUT3 are:
Record 09
Record 10
Record 11
Record 12

SPLIT1R = n => It splits records of 'n' to output dataset. The remaining records it writes to last file.

Example:
OPTION COPY
   OUTFIL FNAMES=(OUTA,OUTB,OUTC),SPLIT1R=5 

With 17 input records, the results produced for OUTA are:
Record 01 
Record 02 
Record 03 
Record 04 
Record 05

The results produced for OUTB are:
Record 06 
Record 07 
Record 08 
Record 09 
Record 10

The results produced for OUTC are:
Record 11 
Record 12 
Record 13 
Record 14 
Record 15 
Record 16 
Record 17