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

ALTER||Identify a generation data set (GDS) with its generation data group (GDG)name followed by the generation and version numbers of the data set(GDGname.GxxxxVyy).See “How to code subparameters” on page xvii for additional considerationson coding entryname.Optional ParametersACCOUNT(account–info)Account is supported only for SMS-managed VSAM or non-VSAM data sets.account–infoUse this to change accounting information and user data for the data set. Itmust be between 1 and 32 bytes; otherwise, you will receive an errormessage.Abbreviation: ACCTADDVOLUMES(volser [ volser])This provides the volumes that are to be added to the list of candidatevolumes. You can use ALTER ADDVOLUMES to add candidate volumes tonon-managed VSAM data sets and SMS-managed VSAM, non-VSAM, andgeneration data sets (GDS). Only nonspecific volumes can be added toSMS-managed, non-VSAM data sets and GDS data sets. If an ALTERADDVOLUMES is done to a data set already opened and allocated, the dataset must be closed, unallocated, reallocated, and reopened before VSAM canextend onto the newly added candidate volume. Adding a nonexistent volumeto the list can result in an error when the data set is extended. Ensure that thevolume exists and is online before attempting to extend the data set.Restriction: This does not work with non-SMS non-VSAM.SMS might not use candidate volumes for which you request specific volserswith the ADDVOLUMES parameter. Sometimes a user-specified volser for anSMS-managed data set results in an error. To avoid candidate-volume problemswith SMS, you can have SMS choose the volser used for a candidate volume.To do this, you can code an * for each volser that you request with theADDVOLUMES parameter. If, however, you request both specified andunspecified volsers in the same command, you must enter the specified volsersfirst in command syntax. The system does not allocate space on candidatevolumes until VSAM extends to the candidate volume. This includesSMS-managed data sets with guaranteed space.Abbreviation: AVOLBUFFERSPACE(size)Provides the amount of space for buffers. The size you specify for the bufferspace helps VSAM determine the size. IBM recommends that the size you giveis equal to or greater than the amount specified in the original definition. If theamount is less, VSAM attempts to get enough space to contain two datacomponent control intervals and, if the data is key-sequenced, one indexcomponent control interval. You can specify BUFFERSPACE only for a catalogor for the data component of a cluster or alternate index. If you useBUFFERSPACE for a catalog, then you must specify the CATALOG parameter.The BUFFERSPACE parameter is ignored for VSAM record-level sharing (RLS)access and DFSMStvs access.Chapter 5. ALTER 57