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

ALTERsizeIs the amount of space for buffers. This helps VSAM determine the size ofthe data component’s and index component’s control interval.Size can be entered in decimal (n), hexadecimal (X'n'), or binary (B'n') form,but must not exceed 16,776,704. The specified size should not be less thanthe space needed to contain two data component control intervals and, ifthe data is key-sequenced, to contain one index control interval. If thegiven size is less than what VSAM requires, it gets it when the data set isopened.Abbreviations: BUFSP or BUFSPCBUFND(number)Gives the number of I/O buffers VSAM is to use for transmitting data betweenvirtual and auxiliary storage. The size of the buffer area is the size of the datacomponent control interval. Use this parameter only to alter the datacomponent of a catalog.The BUFND parameter is ignored for VSAM RLS access and DFSMStvs access.numberIs the number of data buffers you can use. The minimum number is 3, andthe maximum is 255.Abbreviation: BFNDBUFNI(number)Is the number of I/O buffers VSAM uses for transmitting the contents of indexentries between virtual and auxiliary storage for keyed access. The size of thebuffer area is the size of the index control intervals. Use this parameter only toalter the index component of a catalog.The BUFNI parameter is ignored for VSAM RLS and DFSMStvs access.numberIs the number of index buffers you can use. The minimum number is 2and the maximum is 255.Abbreviation: BFNIBWO(TYPECICS|TYPEIMS|NO)Use this parameter if backup-while-open (BWO) is allowed for the VSAMsphere. BWO applies only to SMS data sets and cannot be used withTYPE(LINEAR).If BWO is specified in the SMS data class, the specified BWO value is used aspart of the data set definition, unless BWO was previously defined with anexplicitly specified or modeled DEFINE attribute.TYPECICSUse TYPECICS to specify BWO in a CICS ® environment. For RLSprocessing, this activates BWO processing for CICS or DFSMStvs, or both.For non-RLS processing, CICS determines whether to use this specificationor the specification in the CICS file control table (FCT). For moreinformation about the use of TYPECICS, see CICS System Definition Guide.Exception: If CICS determines that it will use the specification in the CICSFCT, the specification might override the TYPECICS parameter for CICSprocessing.Abbreviation: TYPEC58 z/OS V1R6.0 DFSMS Access Method Services for Catalogs