How to split a Sequential Data Set or PDS member?

Suppose your data set is too large and you want to split it into parts. For instance, this task split the dataset into 3 parts. The first thousand records will fall into data set O1, the second thousand records will fall into data set O2, and the all rest will fall into data set O3

Note: you can change the number of records per part by specifying a different value in SPLIT1R

Split a Sequential Data Set

Specify value for #ds_or_member_you_want_to_split

//  SET DSNAME=#ds_or_member_you_want_to_split                 
//STEP1  EXEC PGM=ICEMAN                          
//SYSOUT DD SYSOUT=*                              
//SORTIN DD DISP=OLD,DSN=&DSNAME                  
//O1     DD DISP=(NEW,CATLG,DELETE),DCB=*.SORTIN, 
//       SPACE=(CYL,(100,100),RLSE),              
//       DSN=&DSNAME..PART01                      
//O2     DD DISP=(NEW,CATLG,DELETE),DCB=*.SORTIN, 
//       SPACE=(CYL,(100,100),RLSE),              
//       DSN=&DSNAME..PART02                      
//O3     DD DISP=(NEW,CATLG,DELETE),DCB=*.SORTIN, 
//       SPACE=(CYL,(100,100),RLSE),              
//       DSN=&DSNAME..PART03                      
//*                                               
//* ADD MORE O'S IF NEEDED (APPEND THEM TO FNAMES)
//*                                               
//SYSIN  DD *                                     
  SORT   FIELDS=COPY                              
  OUTFIL FNAMES=(O1,O2,O3),SPLIT1R=1000              
/*                                                

Split a PDS member

Specify values for #input_ds and #member_you_want_to_split

//  SET DSNAME=#input_pds
//  SET MEM=#member_you_want_to_split              
//STEP1  EXEC PGM=ICEMAN                          
//SYSOUT DD SYSOUT=*                              
//SORTIN DD DISP=OLD,DSN=&DSNAME(&MEM)                  
//O1     DD DISP=(NEW,CATLG,DELETE),DCB=*.SORTIN, 
//       SPACE=(CYL,(100,100),RLSE),              
//       DSN=&DSNAME..&MEM..PART01                      
//O2     DD DISP=(NEW,CATLG,DELETE),DCB=*.SORTIN, 
//       SPACE=(CYL,(100,100),RLSE),              
//       DSN=&DSNAME..&MEM..PART02                      
//O3     DD DISP=(NEW,CATLG,DELETE),DCB=*.SORTIN, 
//       SPACE=(CYL,(100,100),RLSE),              
//       DSN=&DSNAME..&MEM..PART03                      
//*                                               
//* ADD MORE O'S IF NEEDED (APPEND THEM TO FNAMES)
//*                                               
//SYSIN  DD *                                     
  SORT   FIELDS=COPY                              
  OUTFIL FNAMES=(O1,O2,O3),SPLIT1R=1000              
/*  

There is a job that can put these parts back together