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

DEFINE ALTERNATEINDEX/*RELATE(EXAMPLE.SMS1) -DATACLAS(VSALLOC) -NONUNIQUEKEY -UPGRADE)The DEFINE ALTERNATEINDEX command creates an alternate index entry, a dataentry, and an index entry to define the alternate index EXMP1.AIX. The parametersare:vvvvvNAME indicates that the alternate index’s name is EXMP1.AIX.RELATE identifies the alternate index base cluster, EXAMPLE.SMS1. Because anSMS-managed alternate index is being defined, the base cluster must also beSMS-managed.DATACLAS is an installation-defined name of an SMS data class. The data setassumes the RECORG or RECFM, LRECL, KEYLEN, KEYOFF, AVGREC, SPACE,EXPDT or RETPD, VOLUME, CISIZE, FREESPACE, and SHAREOPTIONSparameters assigned to this data class by the ACS routines. This parameter isoptional. If it is not used, the data set will assume the data class defaultassigned by the ACS routines.NONUNIQUEKEY specifies that the alternate key value might be the same fortwo or more data records in the base cluster.UPGRADE specifies that the alternate index is to be opened by VSAM andupgraded each time the base cluster is opened for processing.Define an SMS-Managed Alternate Index: Example 2In this example, an SMS-managed alternate index is defined. Data class is notused, and explicitly defined attributes override any attributes in the default dataclass.//DEFAIX JOB ...//STEP1 EXEC PGM=IDCAMS//SYSPRINT DD SYSOUT=A//SYSIN DD *DEFINE ALTERNATEINDEX -(NAME(EXMP2.AIX) -RELATE(EXAMPLE.SMS2) -KEYS(3 0) -RECORDSIZE(40 50) -KILOBYTES(1600 200) -NONUNIQUEKEY -UPGRADE)/*The DEFINE ALTERNATEINDEX command creates an alternate index entry, a dataentry, and an index entry to define the alternate index EXMP2.AIX. Thecommand’s parameters are:vvvvNAME indicates that the alternate index’s name is EXMP2.AIX.RELATE identifies the alternate index base cluster, EXAMPLE.SMS2. Because anSMS-managed alternate index is being defined, the base cluster must also beSMS-managed.KEYS specifies the length and location of the alternate key field in each of thebase cluster’s data records. The alternate key field is the first three bytes of eachdata record.RECORDSIZE specifies that the alternate index’s records are variable length,with an average size of 40 bytes and a maximum size of 50 bytes.142 z/OS V1R6.0 DFSMS Access Method Services for Catalogs