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

DEFINE USERCATALOGSHAREOPTIONS(crossregion[ crosssystem]|3 4) Abbreviation: SHRSpecifies how a catalog can be shared among users. This specification appliesto both the data and index components of the catalog.crossregionSpecifies the amount of sharing allowed among regions within the samesystem or within multiple systems using global resource serialization(GRS). Independent job steps in an operating system or multiple systemsin a GRS ring can access the catalog concurrently.1 Reserved2 Reserved3 Specifies that the catalog can be fully shared by any number ofusers. With this option, each user opening the catalog as a data setis responsible for maintaining both read and write integrity for thedata the program accesses. User programs that ignore the writeintegrity guidelines can cause VSAM program checks, lost orinaccessible records, uncorrectable catalog errors, and otherunpredictable results. This option places heavy responsibility oneach user sharing the catalog.4 ReservedcrosssystemSpecifies the amount of sharing allowed among systems. Job steps of twoor more operating systems can gain access to the same catalog. To getexclusive control of the catalog’s volume, a task in one system issues theRESERVE macro. The level of cross-system sharing allowed by VSAMapplies only in a multiple operating system environment. You can use:1 Reserved2 Reserved3 Specifies that the catalog is not being shared across systems.SHAREOPTIONS(3 3) would direct the catalog open process tounconditionally bypass the setting of the buffer invalidationindicator. Hence, even though the catalog resided on a sharedDASD device, buffer invalidation would not occur. Thisperformance option must be selected only when the user canguarantee that the catalog is not being shared across multipleprocessors.4 Specifies that the catalog can be fully shared. The integrity of thebuffers and control block structure is maintained by catalogmanagement.STORAGECLASS(class) Abbreviation: STORCLASFor SMS-managed data sets: Specifies the 1-to-8 character name of the storageclass. Your storage administrator defines the names of the storage classes youcan specify. Use the storage class to specify the storage service level to be usedby SMS for storage of the catalog. If STORAGECLASS is specified and SMS isinactive, DEFINE will be unsuccessful.STORAGECLASS cannot be specified as a subparameter of DATA or INDEX.STRNO(number|2)Specifies the number of requests (RPLs) requiring concurrent data setpositioning that VSAM is to be prepared to accommodate.Chapter 19. DEFINE USERCATALOG 209