Glossary


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Term Definition Picture
16MB boundary
A notional boundary in virtual storage. Addresses below the 16MB boundary can be accessed by 24-bit or 31-bit addressing. Addresses on or above the 16MB boundary can be accessed only by 31-bit addressing. The numerical value of 16MB is 2 to the power of 24, or 16,777,216.
ABARS
Aggregate Backup And Recovery Support. Disaster recovery feature within DFSMShsm for automatically creating files containing backups of critical data. The main use of ABARS is to group all the datasets relating to a particular application together.
ABE
ABE is short for "Agent Building Environment". An experimental IBM architecture that provides an open environment in which agents can be added to existing applications, and agent parts, once developed, can be reused across many applications.
Abend
An Abend is short for "Abnormal End". It's a combination of two words, abnormal end. It is an abnormal, rather than planned, end or termination of a computer program because of some problem with how it is running. For example, the program may have attempted to address some computer memory space that it was not given the right to address. This term is more common with mainframe systems.
See also: abend
External link: wiki
abend dump
abend dump is a kind of dump produced when a program ends abnormally.
abnormal end
End of a task, a job, or a subsystem because of an error condition that cannot be resolved by recovery facilities while the task is performed. See abnormal termination.
See also: abnormal end, abend
abnormal termination
This could mean either of the following two: 1. A system failure or operator action that causes a job to end unsuccessfully. Synonymous with abend, abnormal end. 2. The end of processing prior to scheduled termination.
See also: abend
ABR
Area border node
ACB
Acronym ACB can have two meanings: 1. Access Control Block. 2. Application Control Block for IMS applications.
Address Space
The range of addresses available to a computer program or process. Address space can refer to physical storage, virtual storage, or both.
addressing mode
A program attribute that refers to the address length that is expected to be in effect when the program is entered. In z/OS, addresses can be 24, 31, or 64 bits in length.
Adopted Region (CICS)
A CICS region that is incorporated into a platform, but that was originally defined outside the platform environment.
AID
attention identifier.
alias
An alternate label; for example, a label and one or more aliases may be used to refer to the same data element or point in a computer program.
Alternate Key
This is used here in the context of VSAM data sets. In VSAM, a field, other than the primary key, of fixed length and position in a record is called alternate key. A set of alternate keys is used to build an alternate index that provides an alternative or secondary path for access to the data set. There can be any number of alternate keys in a record and they need not be unique.
AMS
A multi function utility named IDCAMS that is used to manage catalogs, devices, and both VSAM and non-VSAM data sets.
AOR
In a CICSPlex configuration, a CICS region devoted to running applications.
APAR
authorized program analysis report.
API
A software interface that enables applications to communicate with each other. An API is the set of programming language constructs or statements that can be coded in an application program to obtain the specific functions and services provided by an underlying operating system or service program.
Application Binding
In a CICS cloud environment, a management bundle that defines an association that maps, or binds, an application to a target platform. An application binding can use CICS bundles to provide additional CICS resources and policy for the applications deployed to them.
Application Layer
In the Open Systems Interconnection (OSI) reference model, the layer that provides means for application processes residing in open systems to exchange information and that contains the application-oriented protocols by which these processes communicate.
APPLID
This is the name by which a logical unit is known in a VTAM network.
AR
AR is a register through which one address space accesses the data in another address space or data space.
ASCII
ASCII is short for American Standard Code for Information Interchange. This is an ANSI standard seven-bit code that was proposed in 1963 and finalized in 1968. The standard ASCII character set consists of 128 decimal numbers ranging from zero through 127 assigned to letters, numbers, punctuation marks, and the most common special characters. The Extended ASCII Character Set also consists of 128 decimal numbers and ranges from 128 through 255 representing additional special characters.
Assembler
A computer program that converts assembly language instructions into object code.
External link: zMainframes
ATM
"Asynchronous Transfer Mode" OR "automatic teller machine".
Auxiliary Storage
All addressable storage other than processor storage.
Backout
Backout, in IT, is a request to remove all changes to resources since the last commit or backout or, for the first unit of recovery, since the beginning of the application. Backout is also called rollback or abort.
See also: Backout, backout, rollback, abort
BAL
Basic Assembler Language.
batch job
A predefined group of processing actions submitted to the system to be performed with little or no interaction between the user and the system. It's just in contrast with interactive job .
Big Blue Zoo
The IBM Laboratories in Rochester, Minnesota.
BINARY
Specified for binary data items. Such items have a decimal equivalent consisting of the decimal digits 0 through 9, plus a sign. Negative numbers are represented as the two's complement of the positive number with the same absolute value. This is basically a numeric encoding scheme used on a mainframe. The amount of storage occupied by a binary item depends on the number of decimal digits defined in its PICTURE clause: For example, the number 10 would normally be stored in memory as x'F1F0'. If the numb
External link: Binary definition from IBM
BIND
Within DB2, the process of extracting and converting embedded SQL statements into a plan. The bind determines access paths to data. BIND can have different meanings for other computer disciplines but we are talking about DB2 in this term.
BizTalk
BizTalk is an industry initiative by Microsoft to promote XML as the common data exchange language for e-commerce and application integration on the Internet. The BizTalk Framework provides guidelines on how to publish schemas (standard data structures) in XML and how to use XML messages to integrate software programs. There is a also product from Microsoft named BizTalk Server.
BLKSIZE
A subparameter of the SPACE parameter in a DD statement. It specifies that space is allocated by blocks
BLL
Base Locator for the COBOL Linkage section.
External link: IBM
BLOB
Binary Large OBject, is a generic term for a file containing some kind of binary data (text, image, document, sound, etc). Typically BLOBs can be transferred and manipulated across a wide range of platforms. BLOBs became available in DB2 mid 1995.
BLOB
Binary Large Object. (DB2)
block
1. A set of consecutive pages on disk. 2. A unit of data storage on a device. 3. A set of contiguous pages in a buffer pool. 4. A string of data elements that is recorded or transmitted as a unit. 5. A sequence of text, commands, or records that are read, written or processed as a unit.
block
A collection of contiguous records recorded as a unit. Blocks are separated by inter-block gaps and each block may contain one or more logical records. A block is a physical record but it may be composed of several contiguous logical records or parts of logical records.
block size
1. The number of data elements in a block. 2. A measure of the size of a block, usually specified in units such as records, words, computer words, or characters. Synonymous with block length and physical record size.
BMP
This is IMS batch processing program that has access to online databases and message queues. BMPs run online, but like programs in a batch environment, they are started with job control language (JCL).
BPAM
Basic partitioned access method.
BSAM
This is the sequential file access method for reading, writing and updating sequential data sets and partitioned data set members.
Buffer
There can be two definition of it: 1. A portion of storage used to hold input or output data temporarily. 2. An area of storage that compensates for the different speeds of data flow or timings of events by temporarily holding a block of data that is waiting to be processed or written to an I/O device.
Buffer Pool
An area of memory into which data pages are read, modified, and held during processing.
Cache
A special-purpose buffer storage, smaller and faster than main storage, used to hold a copy of instructions and data obtained from main storage and likely to be needed next by the processor.
See also: cache, Cache.
Cache
A special-purpose buffer storage, smaller and faster than main storage, used to hold a copy of instructions and data obtained from main storage and likely to be needed next by the processor.
carriage return
1. A keystroke generally indicating the end of a command line. 2. In text data, the action that indicates to continue printing at the left margin of the next line. 3. A character that will cause printing to start at the beginning of the same physical line in which the carriage return occurred.
cartridge
A storage device that consists of magnetic tape, on supply and takeup reels, in a protective housing.
catalog
A directory of files and libraries, with reference to their locations. A catalog may contain other information such as the types of devices in which the files are stored, passwords, and blocking factors.
CEMT
The CICS-supplied transaction that allows checking of the status of terminals, connections, and other CICS entities from a console or from CICS terminal sessions.
CICS bundles
CICS bundles are a unit of deployment for CICS resources that you want to manage together in a CICS region. Management bundles group related CICS bundles together for deployment and management in a CICSplex. Management bundles are installed in a CMAS, and the associated CICS bundles are installed in the CICS regions across the targeted CICSplex (or platform). You can create management bundles for an application or a platform.
COBOL
COmmon Business Orientated Language, is one of the oldest programming languages, primarily designed by Grace Hopper and has been around for eons (since 1959), updated in 1968, 1977 and 1985. There had been development in the language since then and OO COBOL was developed in the 1990's. COBOL is well suited to business applications and used for large batch processes running on mini-computer and mainframes. About 65% of new critical applications use COBOL; several billion lines of COBOL code exist throughou
See also: cobol
External link: wiki
COMP
This is also referred to as BINARY or COMPUTATIONAL. It is usually more efficient to store numeric values in their native binary format rather than to store them in human readable, base ten, format. If the number is stored in its native binary format it can be input from a file and used directly. If it is stored in a base ten format it needs to be converted to a binary format before performing arithmetic computations on it. It will then be necessary to convert it back to base ten for storage to a file.
COMP-3
Usually referred as PACKED-DECIMAL or COMPUTATIONAL-3. This is a numeric encoding scheme, specifically used on a mainframe where each byte contains two digits with the exception of the sign byte that contains one digit and the sign.
COND
Use the COND parameter to test return codes from previous job steps and determine whether to bypass this job step. You can specify one or more tests on the COND parameter, and you can test return codes from particular job steps or from every job step that has completed processing. If any of the test conditions are satisfied, the system evaluates the COND parameter as true and bypasses the job step. If none of the test conditions specified on the COND parameter are satisfied, the system evaluates the COND p
Control Block
It is a block of memory with information in it. They provide the information about the Job, CICS task and a lot more other information. These provide debugging functionality in the event an operating system component or user application fails while the system is running. Types of Control Blocks: 1. System Related Control Blocks 2. Resource Related Control Blocks 3. Job Related Control Blocks 4. Task Related Control Blocks
See also: Control Block
control interval
A fixed-length area of direct access storage in which VSAM stores records and creates distributed free space. Also, in a key-sequenced data set or file, the set of records pointed to by an entry in the sequence-set index record. The control interval is the unit of information that VSAM transmits to or from direct access storage. A control interval always comprises an integral number of physical records.
copybook
Usually, a copybook is a file containing a sequence of code that is included in a source program at compile time. In File Manager, the term “copybook” refers specifically to a file containing descriptions of record structures.
DBCS
A set of characters in which each character is represented by a two-bytes code. Languages such as Japanese, Chinese, and Korean, which contain more symbols than can be represented by 256 code points, require double byte character sets. Because each character requires two bytes, the typing, display, and printing of DBCS characters requires hardware and programs that support DBCS. Contrast with single-byte character set.
DCB
DCB is short for Data Control Block. A Data Control Block is a description of a data-set in a program. A DCB is coded in Assembler programs using the DCB macro instruction; this expands into a large number of "define constant" instructions. High level language programmers use library routines containing DCBs.
Dijkstra's shortest path algorithm
An algorithm named after E.W. Dijkstra that finds the shortest path from a source to a destination.
DISP
Disposition; a JCL DD parameter.
DLL
A file containing executable code and data bound to a program at load time or run time. The code and data in a dynamic link library can be shared by several applications simultaneously.
DSORG
Data set organization. One of the parameters of DCB and DD and in a data class definition.
dump
A dump (suggestive information to solve it) produced when a program ends abnormally.
See also: dump
EAI
Enterprise Application Integration. EAI is a means of sharing data and processes in an unrestricted manner and allowing that data to be accessed by a wide variety of systems.
EBCDIC
EBCDIC stands for 'Extended Binary Coded Decimal Interchange Code'. The EBCDIC character encoding set is used by IBM mainframes. Most other computer systems use a variant of ASCII, IBM mainframes and midrange systems such as the AS/400 use EBCDIC and were designed for ease of use or back level compatibility with punched cards.
EDT
An installation defined representation of the devices that are eligible for allocation. The EDT defines the esoteric and generic relationship of these devices. During IPL, the installation identifies the EDT that z/OS uses. After IPL, jobs can request device allocation from any of the esoteric device groups assigned to the selected EDT. An EDT is identified by a unique ID (two digits), and contains one or more esoteric and generics.
See also: EDT, eligible device table
FICON
Fiber Connection Environment is an optical fiber communication method. It offers channels with high data rate, high bandwidth, increased distance and a large number of devices per control unit for mainframe systems. It can work with, or replace, ESCON links.
See also: FICON, Fiber Connection Environment
FILLER
FILLER is a reserved word, meaning you cannot use the word for naming fields or records other than to define individual memory elements.COBOL restricts the use of FILLER to the Data Division; it does not apply to the Identification, Environment or Procedure divisions. If group variable containing FILLER is initialized using INITIALIZE verb, filler populated with working storage value if any
FTP
File Transfer Protocol is a standard Internet protocol that is the common methodology used to exchange files between computers on the Internet.
GSAM
Generalized Sequential Access Method is a database access method that allows batch application programs to access a sequential data set record that is defined as a database record. This is used in IMS DB application. This database record is handled as one unit, with no segments, fields, or hierarchical structure. Any records to be added are inserted at the end of the database. GSAM does not allow database records to be updated or deleted.
HLASM
HLASM is the assembler language that is currently available for an IBM Mainframe.
IEFBR14
IEFBR14 is a utility program that does very little or just nothing. It sets the return code to zero and returns to the caller. Its purpose is to provide a program that can be specified on the EXEC statement within a JCL member. The subsequent DD statements that are associated with the EXEC statement are processed after that.
External link: wiki
ISPF
ISPF is short for Interactive System Productivity Facility. It is the user interface and supporting programs that come with IBM's zOS, Mainframe operating system. ISPF includes the Dialog Manager (DM), the Program Development Facility (PDF), and the Software Configuration and Library Management (SCLM) facility.
J2EE
J2EE is short for Java 2 Platform Enterprise Edition. This was developed by Sun Micro-systems. J2EE allows developers to build and launch Web-based enterprise applications online.
JES
JES is hort for Job Entry System. JES is a subsystem of zOS (MVS, OS/390). It accepts jobs (units of work) into the system and processes all output data produced by the jobs. Each job is defined by a user and executed according to the rules established by the system administrators. This includes the priority given to the job and the allocation of resources needed to perform the job.
job step
The job control (JCL) statements that request and control execution of a program and that specify the resources needed to run the program. The JCL statements for a job step include one EXEC statement, which specifies the program or procedure to be invoked, followed by one or more DD statements, which specify the data sets or I/O devices that might be needed by the program.
Julian date
A date format that contains the year in positions 1 and 2, and the day in positions 3 through 5. The day is represented as 1 through 366, right-adjusted, with zeros in the unused high-order position.
kernel
The part of an operating system that performs basic functions such as allocating hardware resources.
KSDS
KSDS is hort for key-sequenced data set. It's a VSAM data set whose records are loaded in key sequence and controlled by an index.
LE
Language Environment (more commonly known as LE) is an element of z/OS that provides a common run-time environment and common run-time services for C/C++, COBOL, PL/I, and FORTRAN applications.
licensed program
A software package that can be ordered from the program libraries, such as IBM Software Distribution (ISMD). IMS and CICS are examples of licensed programs.
LIFO
Last-in-first-out.
linked list
A list in which the data elements may be dispersed but in which each data element contains information for locating the next.
Linux
An open-source implementation of UNIX. Linux is distributed free of charge, and it runs on many platforms.
load balancing
The monitoring and management of the workload on servers. If one server exceeds its workload, requests are forwarded to another server with more capacity.
LPA
An area of virtual storage that contains reenterable routines that are loaded at IPL (initial program load) time and can be used concurrently by all tasks in the system.
MAC
A standardized data link layer address required for every port or device that connects to a local-area network (LAN). Other devices in the network use these addresses to locate specific ports in the network and to create and update routing tables and data structures. MAC addresses are 6 bytes long and are controlled by the IEEE.
Mainframe
The IBM Dictionary Of Computing defines "mainframe" as "a large computer, in particular one to which other computers can be connected so that they can share facilities the mainframe provides (for example, a System/370 computing system to which personal computers are attached so that they can upload and download programs and data). The term usually refers to hardware only, namely, main storage, execution circuitry and peripheral units." Reference: IBM
Master Catalog
A catalog that contains extensive data set and volume information that VSAM requires to locate data sets, to allocate and de-allocate storage space, to verify the authorization of a program or operator to gain access to a data set, and to accumulate usage statistics for data sets.
Middleware
Software that connects two separate applications. For example, middleware can connect a database to a Web server. Sometimes it is called as "software glue" too as it provides services to software applications beyond those available from the operating system.
External link: wiki - Middleware (distributed)
MVS
An earlier form of the z/OS operating system. In current usage, the term MVS refers to those services and functions of z/OS other than z/OS UNIX system services, such as those provided by the base control program (BCP), a base element of z/OS.
Object Deck
Object Deck is a module that is the output from a language translator; for example, a compiler or an assembler. This output is used as input to the linkage editor or binder. An object deck is in relocatable format with machine code that is not executable. Before an object deck can be executed, it must be processed by the link-edit utility. It is sometimes referred to as "object code" or just OBJ .
OLTP
Online Transaction Processing. See online processing.
OpenSSH
Open Secure Shell.
OS/390
An operating system developed by IBM for mainframe computers.
Package (DB2)
An object containing a set of SQL statements that have been statically bound and that is available for processing. A package is sometimes also called an application package.
Page
In virtual storage systems, a fixed-length block of instructions, data, or both, that can be transferred between central storage and external page storage.
Page (DB2)
A unit of storage within a table space (4 KB, 8 KB, 16 KB, or 32 KB) or index space (4 KB, 8 KB, 16 KB, or 32 KB). In a table space, a page contains one or more rows of a table. In a LOB or XML table space, a LOB or XML value can span more than one page, but no more than one LOB or XML value is stored on a page.
Page Fault
In z/OS, a program interruption that occurs when a page that is marked "not in central storage" is referred to by an active page.
Parallel Sysplex
A set of z/OS systems that communicate and cooperate with each other through certain multisystem hardware components and software services to process customer workloads.
Partition (DB2)
A portion of a page set. Each partition corresponds to a single, independently extendable data set. The maximum size of a partition depends on the number of partitions in the partitioned page set. All partitions of a given page set have the same maximum size
PDS
PDS is a data set on direct access storage that is divided into partitions, called members, each of which can contain a program, part of a program, or data.
QSAM
QSAM is an access method for storing and retrieving logical records in a continuous sequence. Input data blocks awaiting processing or output data blocks awaiting transfer to auxiliary storage are queued on the system to minimize delays in I/O operations.
RACF
An IBM licensed program that provides access control by identifying users to the system; verifying users of the system; authorizing access to protected resources; logging unauthorized attempts to enter the system; and logging accesses to protected resources.
RDW
For a VB file - the first 4 bytes are called as - Record Descriptor Word.
REXX
REXX is short for REstructured eXtended eXecutor. REXX was initially created and implemented as an independent project by Mike Cowlishaw of IBM. The project started in 1979 and ran through 1982. It was originally a scripting language for the IBM Mainframe but later got many flavors of it.
sequential data set
A data set whose records are organized on the basis of their successive physical positions, such as on magnetic tape. Contrast with direct data set.
SLA
Service Level Agreement or SLA in short is a contract between a customer and a service provider that specifies the expectations for the level of service with respect to availability, performance, and other measurable objectives.
STEPLIB
Steplib specifies the load library where PGM is searched first while executing that step. If load library is not found then it will search is system library. Maximum 255 step library can be coded in the Job. This can be coded for both instream and catalog procedures. If both step library and job library are present then first checks in step library if not found then go for job library. Syntax: //STEPLIB DD DSN=<Dsn name>, DISP=SHR.
Tape Volume
Storage space on tape, identified by a volume label, which contains data sets or objects and available free space. A tape volume is the recording space on a single tape cartridge or reel. See volume .
TIOT
Task Input/Output Table.
VSAM
Virtual Storage Access Method. VSAM is a file management system used on IBM mainframe computers.
VTAM
Virtual Telecommunications Access Method.
WebSphere
Software from IBM used for creating Web-based applications that are supported on many platforms.
z/OS USS
z/OS UNIX System Services is that z/OS services which support a UNIX-like environment. Users can switch between the traditional TSO/E interface and the shell interface. UNIX-skilled users can interact with the system, using a familiar set of standard commands and utilities. Also, z/OS-skilled users can interact with the system, using familiar TSO/E commands and interactive menus to create and manage hierarchical file system files and to copy data back and forth between z/OS data sets and files. Application
Zone Decimal
Zoned-decimal format is format in which each byte of storage can contain one digit or one character. In the zoned-decimal format, each byte of storage is divided into two portions: a 4-bit zone portion and a 4-bit digit portion. See the picture for more clarity. Display

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