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

ALTERALTER ExamplesNOUPGRADESpecifies the alternate index is not to be modified when the its base clusteris modified. NOUPGRADE can be use as an alternate index at any time.Abbreviation: NUPGWRITECHECK|NOWRITECHECKSpecifies whether a data or index component is to be checked by a machineaction called write check when a record is written into it. This parameter canbe specified to alter the data or index components of a cluster, an alternateindex, or catalog.The WRITECHECK setting is ignored when the data set is opened for VSAMRLS or DFSMStvs access.WRITECHECKWrites and reads a record without data transfer, to test for the data checkcondition.Abbreviation: WCKNOWRITECHECKWrites the record onlyAbbreviation: NWCKAlter a Cluster’s Attributes Using SMS Keywords: Example 1In this example, the ALTER command is used with the MANAGEMENTCLASSand STORAGECLASS keywords.//ALTER JOB ...//STEP1 EXEC PGM=IDCAMS//SYSPRINT DD SYSOUT=A//SYSIN DD *ALTER -CLUS.ALTER.EXAMPLE -MANAGEMENTCLASS(VSAM) -STORAGECLASS(FAST) -LOG(ALL) -LOGSTREAMID(LogA)/*The ALTER command modifies some of the attributes of SMS-managed data setCLUS.ALTER.EXAMPLE. The data set is SMS-managed and is about to be used inproduction. Through use in production, it is expected to grow and require anincrease in the frequency of backup, availability and performance. The parametersare MANAGEMENTCLASS, indicating a new management class of VSAM, andSTORAGECLASS, indicating a storage class of FAST.LOG(ALL) specifies that changes to the sphere accessed in RLS and DFSMStvsmode can be backed out and forward recovered using external logs.LOGSTREAMID gives the name of the forward recovery log stream.Roll-In a Generation Data Set: Example 2In this example, the ALTER command is used with the ROLLIN keyword to roll-ina generation data set (GDS) that is currently in the deferred roll-in state.Chapter 5. ALTER 73