DEFINE SPACE command.

Defining data space:

Ø  The purpose of the DEFINE SPACE AMS command is to allocate data space and place it under the control of a user catalog.

Ø  This command will be used if initially catalog was not created with Space parameters or if space assigned to existing catalog is about to end. This space  as indicated earlier will be used for storing VSAM clusters.

Ø  Syntax:

DEFINE  SPACE 
    ({CANDIDATE 
     CYLINDERS(primary[ secondary])  |   à Amount of space to the added
        RECORDS(primary[ secondary]) RECORDSIZE(average maximum)  |
        TRACKS(primary[ secondary])}
     VOLUMES(volser[ volser...])   à Volumes from which data space has to be added to the Control of catalog
     [FILE(ddname)]))

    [CATALOG(catname[/password])] à Catalog to whose control space has to be added

Ø  Example:

//DEFSPAC1 JOB 'JAY MOSELEY',CLASS=A,MSGLEVEL=(1,1),MSGCLASS=A

//IDCAMS   EXEC PGM=IDCAMS,REGION=4096K

//SYSPRINT DD  SYSOUT=A

//MVS802   DD  DISP=OLD,UNIT=3380,VOL=SER=MVS802

//SYSIN    DD  *

  DEFINE SPACE (                                            -

               TRACKS(13244)                                -

               VOLUMES(MVS802)                              -

               FILE(MVS802)                                 -

               )                                            -

               CATALOG(UCMVS802)                             

  IF MAXCC = 0 THEN DO                                      -

        LISTCAT ALL CATALOG(UCMVS802)                       -

     END                                                     

/*                                                           

//              

Ø  CANDIDATE Option:

CANDIDATE, means no actual space is allocated, but the volume is reserved for future use by the catalog, thereby preventing any other VSAM catalog from allocating objects on it.