Loading an RRDS

When an RRDS is being loaded, you must open the associated file for OUTPUT. Use either a DIRECT or a SEQUENTIAL file.

For a DIRECT OUTPUT file, each record is placed in the position specified by the relative record number (or key) in the KEYFROM option of the WRITE statement (see Keys for VSAM data sets).

For a SEQUENTIAL OUTPUT file, use WRITE statements with or without the KEYFROM option. If you specify the KEYFROM option, the record is placed in the specified slot; if you omit it, the record is placed in the slot following the current position. There is no requirement for the records to be presented in ascending relative record number order. If you omit the KEYFROM option, you can obtain the relative record number of the written record by using the KEYTO option.

If you want to load an RRDS sequentially, without use of the KEYFROM or KEYTO options, your file is not required to have the KEYED attribute.

It is an error to attempt to load a record into a position that already contains a record: if you use the KEYFROM option, the KEY condition is raised; if you omit it, the ERROR condition is raised.

In Table 1, the data set is defined with a DEFINE CLUSTER command and given the name PLIVSAM.AJC3.BASE. The fact that it is an RRDS is determined by the NUMBERED keyword. In the PL/I program, it is loaded with a DIRECT OUTPUT file and a WRITE...FROM...KEYFROM statement is used.

If the data had been in order and the keys in sequence, it would have been possible to use a SEQUENTIAL file and write into the data set from the start. The records would then have been placed in the next available slot and given the appropriate number. The number of the key for each record could have been returned by using the KEYTO option.

The PL/I file is associated with the data set by the DD statement, which uses as the DSNAME the name given in the DEFINE CLUSTER command.

 //OPT9#17  JOB
 //STEP1 EXEC PGM=IDCAMS,REGION=512K
 //SYSPRINT DD SYSOUT=A
 //SYSIN    DD *
          DEFINE CLUSTER -
              (NAME(PLIVSAM.AJC3.BASE) -
              VOLUMES(nnnnnn) -
              NUMBERED -
              TRACKS(2 2) -
              RECORDSIZE(20 20))
 /*
 //STEP2  EXEC IBMZCBG
 //PLI.SYSIN      DD *
  CRR1:   PROC OPTIONS(MAIN);
          DCL NOS FILE RECORD OUTPUT DIRECT KEYED ENV(VSAM),
              CARD CHAR(80),
              NAME CHAR(20) DEF CARD,
              NUMBER CHAR(2) DEF CARD POS(21),
              IOFIELD CHAR(20),
              EOF BIT(1) INIT('0'B);
          ON ENDFILE (SYSIN) EOF='1'B;
          OPEN FILE(NOS);
          GET FILE(SYSIN) EDIT(CARD)(A(80));
         DO WHILE (¬EOF);
          PUT FILE(SYSPRINT) SKIP EDIT (CARD) (A);
          IOFIELD=NAME;
          WRITE FILE(NOS) FROM(IOFIELD) KEYFROM(NUMBER);
          GET FILE(SYSIN) EDIT(CARD)(A(80));
          END;
          CLOSE FILE(NOS);
  END CRR1;
 /*
 //GO.NOS DD DSN=PLIVSAM.AJC3.BASE,DISP=OLD
 //GO.SYSIN DD *
 ACTION,G.           12
 BAKER,R.            13
 BRAMLEY,O.H.        28
 CHEESNAME,L.        11
 CORY,G.             36
 ELLIOTT,D.          85
 FIGGINS.E.S.        43
 HARVEY,C.D.W.       25
 HASTINGS,G.M.       31
 KENDALL,J.G.        24
 LANCASTER,W.R.      64
 MILES,R.            23
 NEWMAN,M.W.         40
 PITT,W.H.           55
 ROLF,D.E.           14
 SHEERS,C.D.         21
 SURCLIFFE,M.        42
 TAYLOR,G.C.         47
 WILTON,L.W.         44
 WINSTONE,E.M.       37
 //