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

GlossaryThis glossary defines technical terms andabbreviations used in DFSMS documentation. Ifyou do not find the term you are looking for,refer to the index of the appropriate DFSMSmanual or view the Glossary of Computing Termslocated at:http://www.ibm.com/ibm/terminology/This glossary includes terms and definitions from:vvvThe American National Standard Dictionary forInformation Systems, ANSI X3.172-1990,copyright 1990 by the American NationalStandards Institute (ANSI). Copies may bepurchased from the American NationalStandards Institute, 11 West 42nd Street, NewYork, New York 10036. Definitions areidentified by the symbol (A) after thedefinition.The Information Technology Vocabulary developedby Subcommittee 1, Joint Technical Committee1, of the International Organization forStandardization and the InternationalElectrotechnical Commission (ISO/IECJTC1/SC1). Definitions of published part of thisvocabulary are identified by the symbol (I) afterthe definition; definitions taken from draftinternational standards, committee drafts, andworking papers being developed by ISO/IECJTC1/SC1 are identified by the symbol (T) afterthe definition, indicating that final agreementhas not yet been reached among theparticipating National Bodies of SC1.The IBM Dictionary of Computing, New York:McGraw-Hill, 1994.The following cross-reference is used in thisglossary:See:This refers the reader to (a) a relatedterm, (b) a term that is the expanded formof an abbreviation or acronym, or (c) asynonym or more preferred term.access method services. A multifunction serviceprogram that manages VSAM and non-VSAM datasets, as well as catalogs. Access method servicesprovides the following functions:vvvvvvvvvdefines and allocates space for data sets and catalogsconverts indexed-sequential data sets tokey-sequenced data setsmodifies data set attributes in the catalogreorganizes data setsfacilitates data portability among operating systemscreates backup copies of data setsassists in making inaccessible data sets accessiblelists the records of data sets and catalogsdefines and builds alternate indexesACDS.ACS routine.Seeactive control data setSee automatic class selection routineactive configuration. The configuration currently usedby SMS to control the managed storage in theinstallation.active control data set (ACDS). A VSAM linear dataset that contains an SCDS that has been activated tocontrol the storage management policy for theinstallation. When activating an SCDS, you determinewhich ACDS will hold the active configuration (if youhave defined more than one ACDS). The ACDS isshared by each system that is using the same SMSconfiguration to manage storage. See also source controldata set, communications data set.active data. (1) Data that can be accessed without anyspecial action by the user, such as data on primarystorage or migrated data. Active data also can be storedon tape volumes. (2) For tape mount management,application data that is frequently referenced, small insize, and managed better on DASD than on tape. (3)Contrast with inactive data.ADSP.See automatic data set protectionaggregate group. A collection of related data sets andcontrol information that have been pooled to meet adefined backup or recovery strategy.AACB.See access method control blockAIX. See alternate indexalias. An alternative name for an entry or for amember of a partitioned data set (PDS).access method control block (ACB). A control blockthat links an application program to VSAM or VTAMprograms.alias entry. An entry that relates an alias to the realentry name of a user catalog or non-VSAM data set.© Copyright IBM Corp. 1973, 2004 513