z/OS V1R6.0 DFSMS Access Method Services for Catalogs

ALLOCATEKEYLEN(bytes)This is the length, in bytes, of each of the keys used to locate blocks of recordsin the data set when the data set resides on a direct access device.If an existing data set has standard labels, you can omit this parameter and letthe system retrieve the key length from the standard label. If a key length isnot supplied by any source before you enter, the system assumes an OPENmacro instruction of zero (no keys). This parameter is mutually exclusive withTRTCH.When you want to define the key length or override the key length defined inthe data class (DATACLAS) of the data set, use KEYLEN. The number of bytesis:vv1 to 255 for a record organization of key-sequenced (RECORG(KS))0 to 255 for a data set organization of physical sequential (PS) or partitioned(PO)For PDSEs, you can use 0 or 8. Use 8 only when opening the PDSE for input.Any other value results in an error.KEYOFF(offset)This shows the key position (offset) of the first byte of the key in each record.Use it to define key offset or override the key offset defined in the data class ofthe data set. It is only for a key-sequenced data set (RECORG=KS).Use KEYOFF parameter to allocate both SMS-managed and non-SMS-manageddata sets. If SMS is not active, however, the system checks syntax and thenignores the KEYOFF parameter.LABEL(type)This selects the label processing, one of: SL, SUL, AL, AUL, NSL, NL, LTM, orBLP, which correspond to the JCL label-types.For VSAM data sets, the system always uses SL, whether you define SL or SULor neither. NSL, NL, and BLP do not apply to VSAM data sets.LIKE(model-dsname)This names a model data set. The system uses these attributes as the attributesof the new data set that is being allocated. The model data set must becataloged and must reside on a direct access device. The volume must bemounted when you enter the ALLOCATE command.Note: TSO naming conventions apply when assigning model-dsname.When the ALLOCATE command assigns attributes to a new data set, theseattributes are copied from the model data set if SMS is active:AVGRECSize of average record block (kilobyte,megabyte)BLOCK, AVBLOCK,TRACKS, CYLINDERS Space unitDIRDirectory space quantityDSORGNon-VSAM data set organizationKEYLENKey lengthKEYOFFKey offsetLRECLLogical record lengthRECFMRecord formatRECORGVSAM data set organizationSPACEPrimary and secondary space quantities.Chapter 4. ALLOCATE 39