O

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OAF: See origin address field. See also destination address field, local session identification.
object: In object-oriented design or programming, a concrete realization (instance) of a class that consists of data and the operations associated with that data. An object contains the instance data that is defined by the class, but the class owns the operations that are associated with the data.; A named storage space that consists of a set of characteristics that describe the space and, in some cases, data. An object is anything that occupies space in storage, can be located in a library or directory, can be secured, and on which defined operations can be performed. Some examples of objects are programs, files, libraries, and stream files.; Anything that can be created or manipulated with SQL, such as tables, views, indexes, packages, procedures, triggers, or any other objects that can be created by issuing a CREATE statement.; Any digital content that a user can manipulate as a single unit to perform a task. An object can appear as text, an icon, or both.
object-action paradigm: In VisualAge® RPG, a pattern for interaction in which a user selects an object and then selects an action to apply to that object.
object alter authority: An object authority that allows the user to change the attributes of an object, such as specifying a trigger for a database file or changing the attributes of an SQL package.
object auditing: A function of the IBM® i operating system that creates audit records for specified types of access to an object.
object authority: A specific authority that controls what a system user can do with an entire object. For example, object authority includes deleting, moving, or renaming an object. There are five types of object authorities: object operational, object management, object existence, object alter, and object reference.
object class: In OSI, a way of grouping things of the same type, such as by country, region, or application entity. A set of common object classes has been defined by the ISO/CCITT directory standards.; A categorization or grouping of objects that share similar behaviors and circumstances.
object code: Machine-executable instructions, usually generated by a compiler from source code written in a higher level language. Object code might itself be executable or it might require linking with other object code files.
OBJECT-COMPUTER: In COBOL, the name of an Environment Division paragraph in which the computer environment, within which the program is started, is described.
object computer entry: In COBOL, an entry in the OBJECT-COMPUTER paragraph of the Environment Division that contains clauses that describe the computer environment in which the program is to be started.
object decomposition: The process of breaking an object into its component parts.
object definition file (ODF): In VisualAge RPG, self-contained components that can be shared across applications.
object definition table (ODT): A table built at compile time by the system to keep track of objects declared in the program. The program objects in the table include variables, constants, labels, operand lists and exception descriptions. The table resides in the compiled program object.
object description: The characteristics (such as name, type, and owner name) that describe an object.
object descriptor: A data structure that identifies a particular WebSphere® MQ object. Included in the descriptor are the name of the object and the object type.
object distribution: A function that allows a user to send source and data files, save files, job streams, spooled files, and messages to another user, either locally or on an SNADS network.
object existence authority: An object authority that allows the user to delete the object, free storage of the object, save and restore the object, transfer ownership of the object, and create an object that was named by an authority holder.
object handle: The identifier or token by which a program accesses the WebSphere MQ object with which it is working.
object hierarchy: A way of illustrating relationships among objects. Each object that appears in a level below another object is an example of the upper object.
object ID: An ISO-defined format for identifying elements within an OSI network. An object ID consists of a string of integers. The integers in the string can identify a particular standards body, an enterprise, or the type or value of an object. An object ID is intended to be a universal identifier of an object. Examples of values that are specified in object ID format are abstract syntaxes, application context names, and application process titles.
object identifier (OID): A hierarchical sequence of numbers that uniquely identifies an object.
object information repository (OIR): In System Manager, the information about each object that identifies which product it is associated with, such as the release level, option, and the load identifier.
object management authority: An object authority that allows the user to specify the authority for the object, move or rename the object, and add members to database files.
object of entry: In COBOL, a set of operands and reserved words, within a Data Division entry of a COBOL program, that immediately follow the subject of the entry.
object operational authority: An object authority that allows the user to look at the description of an object and use the object as determined by the user's data authorities to the object.
object-oriented programming: A programming approach based on the concepts of data abstraction and inheritance. Unlike procedural programming techniques, object-oriented programming concentrates not on how something is accomplished but instead on what data objects comprise the problem and how they are manipulated.
object-oriented user interface: In VisualAge RPG, a type of user interface that implements the object-action paradigm.
object owner: A user who creates an object or to whom the ownership of an object was reassigned. The object owner has complete control over the object.
object program: In the original program model (OPM), a set of instructions in machine-readable form. The object program is produced by a compiler from a source program. In the Integrated Language Environment® (ILE) model, an object program is the result of binding modules together.
object reference authority: An object authority that allows the user to specify a database file as the first level in a referential constraint.
Object Request Broker (ORB): In object-oriented programming, software that serves as an intermediary by transparently enabling objects to exchange requests and responses.
object subclass: An object created from another object and from which the properties of the original object are inherited.
object superclass: The object from which subclass objects are created. The properties of the superclass object are inherited by the superclass object.
object time: In COBOL, the time at which a program is run.
object type: In query management, the substring following the query command name that specifies the type of query object to be processed.
observability: The property of an object, which is derived from data stored with the object, that allows source to be retrieved from the object, allows the object to be re-created without being recompiled, and allows the object to be symbolically debugged.
obstruction: An object that prevents something from working correctly.
OCR: See optical character recognition. See also magnetic ink character recognition.; See overcommitment ratio.
octet: A byte composed of eight binary elements.
ODBC: See Open Database Connectivity.
odd/even bus pair: An optical link card supports a pair of buses; one has an even number and the other has an odd number (for example, bus 2 and 3).
odd positive acknowledgment
ODF: See object definition file.
ODP: See open data path. See also shared file.
ODT: See object definition table.
OEM: See original equipment manufacturer.
offline: Pertaining to the operation of a device that is not under the control of a system. See also online.
offset: The number of measuring units from an arbitrary starting point to some other point.
offset pie slice: In Business Graphics Utility, a slice that is slightly removed from a pie chart to emphasize it.
offset stacking: A function that allows the printed output pages to be offset for easy separation of the print jobs.
ohm: A unit of measure of electrical resistance.
OID: See object identifier.
OIR: See object information repository.
omit function: A system function that determines which records from a physical file are to be omitted from a logical file. See also select function.
OnDemand: A licensed program that provides a set of archive features that allows you to store large volumes of data or retrieve selected data. This data can be on disk, can be optical, or can be on tape storage media. OnDemand provides computer output to laser disk and extended archiving functions for a variety of data types.
one-phase commit: A protocol that is used by a sync point manager to commit a transaction when only resources that are managed as a single entity are changed during the transaction. For example, one-phase commit would be used when a single database on a single system is changed. If either the system or communications fail during a one-phase commit, the sync point manager may not be informed of whether the changes were committed or rolled back.
one-way hash: In cryptography, pertaining to a type of algorithm that can be applied to a buffer of data to produce a fixed string of digits. Cryptographic programs often apply one-way hash algorithms against a set of data and often compare the results with previously generated hash values.; A function that converts a message into a fixed string of digits.
online: Pertaining to the operation of a functional unit or device that is under the control of the system or of a host. See also offline.
online information: Information on the display screen that explains displays, messages, and programs.
online test: A standardized set of tests for BSC. The tests are used to ensure the proper operation and correct working of the data link (lines and modems) portion of the total system.
OOB: See out-of-band.
op code: See operation code.
open: To make a file available to a program for processing. See also close.
Open Database Connectivity (ODBC): A standard application programming interface (API) for accessing data in both relational and nonrelational database management systems. Using this API, database applications can access data stored in database management systems on a variety of computers even if each database management system uses a different data storage format and programming interface.
open data path (ODP): A control block created when a file is opened. An ODP contains information about the merged file attributes and information returned by input or output operations. The ODP only exists while the file is open. See also shared file.
open feedback area: In the C language, an area containing general information about the opened file, including its name, library, and file type. This area also contains specific information about the file type, which applicable fields depend on, and about each device and communications session defined for the file.
open mode: In COBOL, the condition of a file after the program processes an OPEN statement for that file and before the program processes a CLOSE statement for that file. The particular open mode is specified in the OPEN statement as either INPUT, OUTPUT, I-O, or EXTEND.
open system: A system whose characteristics comply with standards made available throughout the industry and that therefore can be connected to other systems complying with the same standards.
open systems interconnection (OSI): The interconnection of open systems in accordance with standards of the International Organization for Standardization (ISO) for the exchange of information.
open systems interconnection architecture (OSI architecture): Network architecture that adheres to the particular set of ISO standards relating to Open Systems Interconnection.
open systems interconnection network (OSINET): A test network sponsored by the National Institute of Standards and Technology. The goal of OSINET is to provide a common set of OSI protocols that allow all participants to communicate with each other for development and research, and for interoperability testing.
open systems interconnection reference model (OSI-RM): The seven-layer basic reference model that ISO 7498 (CCITT X.200) uses to describe how open systems should act and interact. The three primary kinds of interactions described in that reference model are the interactions: (a) inside layers, (b) between layers, and (c) between open systems.
operand: An entity on which an operation is performed.
operating: In finance communications, the that contains the operating image. The operating is used to load the operating image to the main storage of the 4701 Finance Communication Controller.
operating image: In finance communications, a collection of the 4701 Finance Communication Controller microcode, user system configuration, and user application programs.
operating system (OS): A collection of system programs that control the overall operation of a computer system.
Operating System/400® (OS/400®): The IBM licensed program that can be used as the operating system for iSeries servers prior to Version 5 Release 3. See also iSeries, IBM i, System i5®.
Operational Assistant: A part of the operating system that provides a set of menus and displays for end users to do commonly performed tasks, such as working with printer output, messages, and batch jobs.
operational descriptor: Information about an argument's size, shape, and type, which is passed by the system to the called procedure. This information is useful when the called procedure cannot precisely anticipate the form of the argument, for example, different types of strings.
operational sign: In COBOL, an algebraic sign associated with a numeric data item or a numeric constant that indicates whether the item is positive or negative.
operation code (op code): A code used to represent the operations of a computer.; In RPG, a word or abbreviation, specified in the calculation specifications, that identifies an operation.
Operations Console: A feature of System i® Access for Windows that provides the ability for a System i console to be either a local or a remote personal computer. With Operations Console, a system administrator, for example, can access the console from home. See also local console, remote console, twinaxial console.
operations management: In System Manager, the discipline that manages the use of systems and resources to support enterprise information-processing work loads.
operator: In the C, COBOL, and REXX languages, a token that specifies the type of action to be done on one or more terms. The four types of operators are concatenation, arithmetic, comparison, and logical.
operator panel: See control panel.
operator precedence: In programming languages, an order relationship that defines the sequence of the application of operators with an expression.
OPM: See original program model.
optical character recognition (OCR): Character recognition that uses optical means to identify graphic characters. See also magnetic ink character recognition.
optical device: Either a CD-ROM drive, a digital video disk (DVD), or both.
optical disk: A disk that uses laser technology for data storage and retrieval.
optical disk cartridge: A plastic case that protects and holds an optical disk, and permits insertion into an optical disk drive.
optical drive: The part used to seek, read, and write data on an optical disc. An optical drive may reside in an optical library or as a stand-alone unit.
optical image file: A byte-stream file that contains a bit-for-bit mapping of an ISO9660 format CD-ROM or Universal Disk Format (UDF) DVD.
optical library: A set of optical disk drives and optical disks defined to a source control data set (SCDS). An optical library can be a physical library with the optical drives and optical disks residing within the same storage device, or a pseudo library that consists of operator-accessible drives and shelf-resident optical disks.
optical redundancy: A second optical path used to keep the system operational when a hardware failure occurs.
optical scanner: A device that scans optically and usually creates an analog or digital signal.
optical volume: Storage space on an optical disk, identified by a volume label.
optical volume set: Both sides of a double-sided volume optical disc containing optically stored data.
OptiConnect: A System i system area network (SAN) that allows high-speed links between systems in a System i cluster. OptiConnect provides three hardware technologies (SPD OptiConnect, high-speed link (HSL) OptiConnect, and virtual OptiConnect) that can exist simultaneously on a single cluster node.; A feature of the IBM i operating system that allows a user to connect multiple System i systems by using SPD bus, high-speed link (HSL) loop, or virtual interpartition technologies.
optimization level: The level of efficiency for processing a program, which is determined by the application programmer. When the code is optimized on the system, the system uses processing shortcuts to reduce the amount of system resources necessary to produce the same output. The processing shortcuts are then translated by the system into machine code, which allows the program to run more efficiently.
optimized dialogue transfer: In OSI, a quality-of-service value provided by the session layer that enables the concatenation of multiple application entity requests--such as data and control information requests--when transferring them. The concatenation increases data throughput.
optional file: In COBOL, a file that is declared as being not necessarily present each time the program is started.
optional user facilities: Facilities defined within the CCITT Recommendation X.25 that a user of a packet-switching data network can request when establishing a virtual circuit.
optional word: In COBOL, a reserved word included in a specific format only to improve the readability of a COBOL statement or entry.
option indicator: A 1-character field that is passed with an output data record from a program to the system that is used to control the output function, such as controlling which fields in the record are displayed.
ORB: See Object Request Broker.
ordinary identifier: An uppercase letter followed by zero or more characters, each of which is an uppercase letter, a number, or the underscore character. An ordinary identifier should not be a reserved word.
ordinary token: A numeric constant, an ordinary identifier, a host identifier, or a keyword.
organizational unit: A unit within an organization, such as a company, that identifies a particular set of users.
origin address field (OAF): In SNA, a field in a format identification 0 (or format identification 1) transmission header that contains the network address of the originating location. In a format identification 2 heading, the field is called origin address field prime (OAF'). See also destination address field, local session identification.
original database: In a remote journal network, the data files that reside on a primary system. During normal operations, applications make changes to the original database on the primary system.
original equipment manufacturer (OEM): A manufacturer of equipment that can be marketed by another manufacturer.
original program model (OPM): The set of functions for compiling source code and creating high-level language programs before the Integrated Language Environment (ILE) model was introduced.
originator address: A string of data representing the address of the originator of the message. The contents and format of the string are not defined by the mail server framework. The address type associated with the originator address is assumed to define the contents of the originator address field.
originator/recipient name (O/R name): In OSI X.400, the name of the user (the originator and recipient of messages) and other attributes.
O/R name: See originator/recipient name.
orphaned mutex: A mutual exclusion lock that was held by a thread when that thread ended. This makes associated application data or thread resources inconsistent.
OR relationship: The specification of conditioning indicators such that the conditioned operation is done when any one of the conditions is met.
OS: See operating system.
OS/400: See Operating System/400. See also iSeries, IBM i, System i5.
OSI: See open systems interconnection.
OSI application: An application that communicates over an OSI network.
OSI architecture: See open systems interconnection architecture.
OSI Communications Subsystem: The IBM licensed program that provides communications support for open systems interconnection (OSI) on the system.
OSI File Services: The IBM licensed program that provides open systems interconnection (OSI) file transfer, access, and management on the system.
OSI Message Services: The IBM licensed program that provides message services (X.400) for open systems interconnection (OSI) on the system.
OSINET: See open systems interconnection network.
OSI network: A data communications network that exchanges data according to the OSI protocols.
OSI protocols: The set of rules for exchanging data defined by the ISO in accordance with the OSI reference model.
OSI-RM: See open systems interconnection reference model.
outbound DTE attribute: In OSI, an attributes defined by the local node to regulate communications with an adjacent node over an X.25 subnetwork. The attribute affects only the communications over the subnetwork between the local and adjacent nodes; it does not regulate end-to-end communications.
outbound intrusion: See extrusion.
outbound raw attack: An outbound packet that uses a nonstandard protocol.
outline box: In VisualAge RPG, a rectangular box positioned around a group of controls to indicate that all the controls are related.
out-of-band (OOB): Pertaining to user-specific data that has meaning only for connection-oriented (stream) sockets. The server generally receives stream data in the same order that it was sent. OOB data is received independent of its position in the stream (independent of the order in which it was sent).
output: The result of processing data. Output can be displayed, printed, stored, or passed to another process.
output field: A field specified in a display file, database file, printer file, or ICF file that is reserved for the information processed by a program. See also input field.
output file: In COBOL, a file that is opened in either the output mode or extend mode.; A database or device file that is opened with the option to allow records to be written.
output indicator: In RPG, an indicator used to define the conditions under which an output record or an output field in the output specifications is written. An output indicator must be previously defined before it is used in the output specifications.
output/input field: A field specified in a database, display, or ICF file that can be used for both the information supplied to the program and the information received from the program during processing.
output mode: In COBOL, the state of a file after running an OPEN statement, with the OUTPUT or EXTEND phrase specified for that file, and before running a CLOSE statement, without the REEL or UNIT phrase specified for that file.
output PIN-protection key: In Cryptographic Support, a key encrypting key used to encrypt a PIN before it is sent to another location.
output procedure: In COBOL, a set of programs to which control is given after a sort or merge operation.
output queue: An object that contains a list of spooled files to be written to an output device, such as a printer or a . The system-recognized identifier for the object type is *OUTQ.
output specifications: In RPG, the means by which the programmer describes the output records and their fields or adds RPG functions to an externally described output file.
output stream: In RJE, data received from the host system to the attached devices (for example, control characters, data files, and messages). See also input stream.
overcommitment ratio (OCR): The ratio of the number of active users and the amount of main storage they use to the size of the interactive main storage pool.
overflow: The condition that occurs when data cannot fit in the designated field.; A condition that occurs when a portion of the result of an operation exceeds the capacity of the intended unit of storage.
overflow indicator: In RPG, an indicator that signals when the overflow line on a page has been printed or passed. The indicator (OV and OA through OF) can be used to specify which lines are to be printed on the next page.
overlapping fields: Fields in the same display or printer record that occupy the same positions on the display or page. Option indicators can be used to select which of the overlapping fields is to be displayed or printed.
overlay: To write over (and therefore destroy) an existing file.; A program segment that is loaded into main storage and replaces all or part of a previously loaded program segment.; In Performance Tools, a graph that is placed on top of another graph so that a user can view both graphs at the same time.
Overlay Utility: In AFP Utilities, an interactive tool that allows the user to create an overlay.
overprovisioning: A way to address current limitations of best-effort networks by allowing for more bandwidth than expected network peak requirements. Overprovisioning increases the probability, but does not guarantee the quality, of the transmission of time-sensitive and bandwidth-intensive applications.
override: The attributes specified at run time that change the attributes specified in the file description or in the program.; In object-oriented programming, to define a new class behavior by changing a method inherited from a parent class.; To specify attributes at run time that change the attributes specified in the file description or in the program.
overrun: The loss of data because a receiving device is unable to accept data at the rate it is transmitted.
overstrike: Pertaining to a character or symbol that occupies the same space as another character or symbol.
owner: The user who creates an object or is named the owner of an object.
owner authority: The authority that the object's owner has to the object. See also primary group authority, private authority, public authority.