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

size. Extended addressability data sets must beallocated with DSNTYPE=EXT and EXTENDEDADDRESSABILITY=Y.extended format. The format of a data set that has adata set name type (DSNTYPE) of EXTENDED. Thedata set is structured logically the same as a data setthat is not in extended format but the physical formatis different. Data sets in extended format can be stripedor compressed. Data in an extended format VSAMKSDS can be compressed. See also striped data set,compressed format.extent. A continuous space allocated on a DASDvolume occupied by a data set or portion of a data set.An extent of a data set contains a whole number ofcontrol areas.Ffield. In a record or a control block, a specified areaused for a particular category of data or controlinformation.filtering. The process of selecting data sets based onspecified criteria. These criteria consist of fully orpartially-qualified data set names or of certain data setcharacteristics.GGDG.GDS.See generation data groupSee generation data setgeneration data group (GDG). A collection ofhistorically related non-VSAM data sets that arearranged in chronological order; each data set is ageneration data set.generation data set.data group.One generation of a generationgeneric unit name. A name assigned to a class ofdevices with the same geometry (such as 3390).Contrast with esoteric unit name.global resource serialization (GRS). A component ofz/OS used for serializing use of system resources andfor converting hardware reserves on DASD volumes todata set enqueues.GRS.HSee global resource serializationhardware configuration definition (HCD). Aninteractive interface in MVS that enables an installationto define hardware configurations from a single pointof control.hardware configuration definition (HCD). Aninteractive interface in z/OS that enables an installationto define hardware configurations from a single pointof control.IICSF.IDRC.See Integrated Cryptographic Service FacilitySee improved data recording capabilityimproved data recording capability (IDRC). Arecording mode that can increase the effective cartridgedata capacity and the effective data rate when enabledand invoked. IDRC is always enabled on the 3490Etape subsystem.Integrated Cryptographic Service Facility (ICSF). Alicensed program that runs under z/OS and providesaccess to the hardware cryptographic feature forprogramming applications. The combination of thehardware cryptographic feature and ICSF providessecure high-speed cryptographic services.inactive data. (1) A copy of active data, such as vitalrecords or a backup copy of a data set. Inactive data isnever changed, but can be deleted or superseded byanother copy. (2) In tape mount management, data thatis written once and never used again. The majority ofthis data is point-in-time backups. (3) Objectsinfrequently accessed by users and eligible to be movedto the optical library or shelf. (4) Contrast with activedata.indexed VTOC. A volume table of contents with anindex that contains a list of data set names and freespace information, which allows data sets to be locatedmore efficiently.index entry. A catalog entry that describes the indexcomponent of a key-sequenced cluster, alternate index,or catalog. An index entry contains the indexcomponent’s attributes, passwords and protectionattributes, allocation and extent information, andstatistics.index level. A set of index records that order and givethe location of records in the next lower level or ofcontrol intervals in the data set that it controls.index record. A collection of index entries that areretrieved and stored as a group. Contrast with datarecord.index set. The set of index levels above the sequenceset. The index is comprised of the index set and thesequence set.integrity.See data integrity.Interactive System Productivity Facility (ISPF). AnIBM licensed program that serves as a full-screen editorand dialogue manager. Used for writing application518 z/OS V1R6.0 DFSMS Access Method Services for Catalogs