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

DEFINE ALTERNATEINDEXNAME(entryname)The alternate index’s entryname or the name of each of its components. Theentry name specified for the alternate index as a whole is not propagated tothe alternate index’s components.You can define a separate entry name for the alternate index, its datacomponent, and its index component. If you do not give a name for the dataor index component, one is generated. For more information about thesystem-generated name format, see z/OS DFSMS: Managing Catalogs.When the alternate index, data component, and index component areindividually named, each can be addressed.RELATE(entryname)Names the alternate index base cluster. The base cluster is an entry-sequencedcluster or a key-sequenced cluster to which the alternate index is to be related.You cannot relate an alternate index to a reusable cluster, to a relative recordcluster, to an extended addressability ESDS, or to a VVDS (data set name'SYS1.VVDS.Vvolser'). An SMS-managed alternate index has the samemanagement class and storage class as its base cluster.Select the entryname so that the multilevel alias facility selects the same catalogas the one containing the related data set name.Abbreviation: RELCYLINDERS(primary[ secondary])|KILOBYTES(primary[ secondary])|MEGABYTES(primary[ secondary])|RECORDS(primary[ secondary])|TRACKS(primary[ secondary])The amount of space in cylinders, kilobytes, megabytes, records, or tracksallocated to the alternate index from the volume’s available space. A kilobyteand megabyte allocation resolves to either tracks or cylinders; records areallocated to the nearest track boundary.Exception: If allocation resolves to tracks, the space is contiguous. For moreinformation, see “Optimizing Control Area Size” in z/OS DFSMS: Using DataSets.Requests for space are directed to DADSM and result in a format-1 DSCB forthe data and index component entries.If you do not use the MODEL parameter or the RECATALOG parameter, youmust include one, and only one, of these parameters: CYLINDERS,KILOBYTES, MEGABYTES, RECORDS, or TRACKS.The space parameter is optional if the cluster is SMS-managed, but if you donot use it, space can be modeled or defaulted by SMS. If it is not determined,the DEFINE is unsuccessful.To maintain device independence, do not use the TRACKS or CYLINDERSparameters. If you do not use TRACKS or CYLINDERS for an SMS-managedalternate index, space is allocated on the volume selected by SMS.When you do not divide the data component into key ranges, and more thanone volume is given, the primary amount of space is allocated only on the firstvolume when the component is defined. When the component increases toextend to additional volumes, the first allocation on each overflow volume isthe primary amount.Chapter 13. DEFINE ALTERNATEINDEX 129