This site contains terms and definitions from many IBM software and hardware products as well as general computing terms.
In data communications, a specification of the CCITT that defines the list of definitions for interchange circuits between data terminal equipment (DTE) and data circuit-terminating equipment (DCE).
In data communications, a specification of the CCITT that defines the automatic answering equipment or parallel automatic calling equipment or both on the General Switched Telephone Network, including procedures for disabling of echo controlled devices for both manually and automatically established calls.
In data communications, a specification of the CCITT that defines the list of definitions for interchange circuits between data terminal equipment (DTE) and data circuit-terminating equipment (DCE) at data rates of 48 kilobits per second.
See variance at completion.
To check a policy set for conditions that can cause problems if that policy set becomes the active policy set. For example, the validation process checks whether the policy set contains a default management class.
- An optional final stage of model building in which the refined model from the testing stage is validated against a further subset of the source data. See also model building, testing, training.
- The checking of data or code for correctness or for compliance with applicable standards, rules, and conventions.
- In Sterling Order Management, a business scenario. A business user defines and manages business detection and override rules against a validation.
- The process of verifying that a certain test succeeded or failed to achieve its goal.
- The process of comparing an entity against the specified requirements to determine if it meets each and every requirement.
A mechanism for verifying whether the actual value of a variable at run time corresponds to the expected value of that variable. See also timing constraint.
An i5/OS object that can store an identifier, encrypted data, and free-form data. This type of object is often used to store user ID and password information about remote users. The system-defined object type is *VLDL.
- A rule defined on an attribute definition that specifies the criteria that must be met by the data stored in an instance of this attribute for that attribute to be valid. See also attribute definition, attribute instance.
- In Sterling Order Management, a business detection rule or limiting condition that is established to address a common business scenario. For example, one could place a limit of 10 on a sale item, or limit the age of a purchaser to 18 years or older. As long as a transaction is within the limits of the validation rule, it proceeds without intervention.
valid end type
An entity type that conforms to the end constraints of a particular link. See also end constraint.
An entry by an operator that falls on or within the range of valid values that are configured during survey authoring. A valid entry enables the system to proceed to the next available variable or question for entry.
- Verification that object names used in DB2 for i5/OS SQL statements exist on a system.
- Verification of the contents of a field.
- In GL, an input/output device that returns a value in a range. For example, a mouse is logically two valuators: the x position and the y position.
- An input device that provides a scale value; for example, a thumb wheel or a potentiometer.
- A set of characters or a quantity associated with a parameter or name.
- The content of a variable, parameter, special register, or field.
- When standardizing data, a phrase, a word, or a set of one or more characters that is used for analyzing and processing text. See also class, pattern, token.
- The smallest unit of data manipulated in SQL.
- The content of a data item. The value can be an integer, a string, or the handle of another data bag.
- A specific data item at the intersection of a column and row.
- In DCE X/Open Object Management (XOM), an arbitrary and complex information item that can be viewed as a characteristic or property of an object.
- In programming, the alphabetic or numeric contents of a variable or a storage location.
value-added network (VAN)
A network that provides services and capabilities to its subscribers that are not readily available on public networks. For example, a value-added network might offer protocol conversion or access to a specialized database.
value-added service (VAS)
An activity that is performed in response to a customer demand. Value added services can be activities performed on a product before the product is delivered to the customer, or a provided service that is performed at the customer site. See also ticketing.
A set of interdependent companies that work closely together to manage the flow of products and services along the entire value-added channel. The "chain" is made up of the variety of links, including manufacturers, consultants, distributors, resellers, and service providers, required to provide the intended value to the final customer.
value chain business model
A business model that supports transactions involving multiple enterprises or parties. Products, goods, services, or information are delivered through the parties of the value chain from producers to end users. See also demand chain, supply chain.
See value-added network.
See value-added reseller.
- A user-defined default value specified in an access definition.
- Data that passes from one step to another in a process. For example, a process that automates escalation of customer issues needs variables to hold information, such as the customer's name and the issue ID.
- A specific attribute in the case data set that can pertain to a question or combination of questions, responses, and so on based on the question type. For example, a variable can represent a question on a printed questionnaire and store the responses to the question.
- A representation of a changeable value. See also global variable, term placeholder, variable scope.
- In Rational Team Concert, a user-defined parameter that can be included in the command and option stings of the translator.
- An entity that represents an unknown quantity that is determined as a result of solving the mathematical program containing the variable. In this context, a variable may be governed by one or more formal constraints. See also data element, decision variable, script variable.
A builder that produces a component analogous to a programming variable for the web application. Within the variable builder, the type of variable can be declared, based on the variable content.
variable component name
A component of a group type that includes the literal at the end of the name because it represents more than one type. The literal ANY acts like a wild card, which represents any type whose name could appear in that place.
- In printers, data that can vary, for example, the names and addresses in form letters. See also constant data.
- In AFP Utilities, an element in the record layout whose value is represented in the database file. See also fixed data.
The length of a record or field that can be changed. See also fixed length.
- In distributed data management (DDM) and Distributed FileManager (DFM), a record whose length can be changed after it has been written to a file. Variable-length records are normally used in reference to count-key-data (CKD) and extended count key data (ECKD) formats. See also fixed-length record.
- A record having a length independent of the length of other records with which it is logically or physically associated. See also fixed-length record.
- In COBOL, a record associated with a file whose file description entry or sort-merge description entry permits records to contain a varying number of character positions.
See varying-length string.
variable message sign (VMS)
A traffic control device whose message can be changed manually, electrically, mechanically, or electromechanically to provide motorists with information about traffic congestion, traffic crashes, maintenance operations, adverse weather conditions, roadway conditions, organized events, or other highway features (for example, drawbridges, toll booths, and weigh stations).
variable-occurrence data item
In COBOL, a table element that is repeated a variable number of times. Such an item must contain an OCCURS DEPENDING ON clause in its data description entry, or be subordinate to such an item.
In architecture, a method used to assign a character increment dimension of varying size to space characters. The space characters are used to distribute white space within a text line. The white space is distributed by expanding or contracting the dimension of the variable space character's increment dependent upon the amount of white space to be distributed.
variable space character
In architecture, the code point assigned by the data stream for which the character increment varies according to the semantics and pragmatics of the variable space function. This code point is not presented, but its character increment parameter is used to provide spacing.
variable space character increment
In architecture, the variable value associated with a variable space character. The variable space character increment is used to calculate the dimension from the current presentation position to a new presentation position when a variable space character is found.
variable space font
See proportionally spaced font.
In a REXX exec, a symbol that is assigned a value by the user or in some cases by the REXX interpreter. The value of a variable symbol can be tested and changed using control statements.
- A version of an artifact or a product that is identified by a specific set of characteristics that distinguish it from other artifacts or products in the product line, where each variant can exist at the same time as other versions of the artifact or product. See also product, product line, variation point.
- A version of a storage bucket. Each variant can have a different configuration (for example, encryption settings, lifespan settings).
An action that is derived from another action so that the content of the action can vary. A field in the variant action object can derive its value in a different way from the way that the same field derives its value in the base action object.
- A user-defined function that might return different values when passed the same arguments. A variant function can contain SQL statements. See also nonvariant function.
- See non-deterministic function.
The fourth, optional level in the software hierarchy, located after product, version, and release. A release of a product can have multiple variations. See also modification level, parent software, release, software hierarchy, version.
An aspect of a design with multiple potential values that, when chosen, defines one of the characteristics that distinguish one product from another within a product line. See also product line, variant.
A product that is available in different variations. For example, a shirt maybe be available in different size variations, such as small, large, and extra large, and color variations, such as black, white, and red.
- A character, graphic, or binary string with a length that is not fixed but that can range within set limits.
- A character or graphic string whose length is not fixed, but variable within limits. See also fixed-length string.
To change the status of a device or library from online to offline. When a device or tape library is offline, no data can be accessed on the device or tape library. Varying an optical library offline does not affect the online or offline status of the drives it contains.
See value-added service.
See Visual Basic.
See virtual circuit.
See virtual card.
See virtual channel identifier.
See V-type constant.
See virtual device driver.
A numerical expression that enables a consistent way to evaluate the vulnerability of your applications. V-Density is calculated by relating the number and criticality of vulnerabilities and exceptions to the size of the application or project being analyzed.
See host mapping.
See vital product data.
See visual data stream.
- A linearly ordered collection of scalars of the same type. Each scalar is said to be an element of the vector. See also array, scalar.
- An array of one dimension.
- In the GDDM function, a directed line segment, which is a straight line between two points.
- In SNA, a data structure containing three fields: a length field that specifies the length of the vector in which it is contained, an identifier or type field, and a value field. The value field may contain subvectors.
See scattered read.
A digital image that is made up of geometric graphic elements such as points, arcs, and lines that are defined by mathematical formulas. This mathematical formulation allows for the size of the graphic to be changed without a loss in its image quality.
An instruction, such as a load, store, arithmetic, or logical instruction, that operates on vectors residing in storage or in a vector register in the vector facility. See also scalar instruction.
vector symbol set (VSS)
In the GDDM function, a set of characters each of which is treated as a small picture and is described by a sequence of lines and arcs. Characters in a vector symbol set can be drawn to scale, rotated, and positioned precisely. See also image symbol set.
A Java-based template engine that provides a simple and powerful template language to reference objects defined in Java code. Velocity is an open source package directed by the Apache Project.
- The speed at which data is acquired and used.
- The turnover rate of an individual SKU. SKUs that sell quickly with quick turnover are high velocity items.
- The measure of how fast work should run when ready, without being delayed by contention for managed resources.
A code that identifies the velocity of a SKU. This code is used in location selection in a warehouse to ensure that higher velocity items are stored closer to the shipping area than low velocity items.
- A service provider that provides the telecom services to customers.
- A person or company that supplies materials or services to another person or company.
In License Use Management, the identifier for a vendor of licensed products that enables license servers to distinguish among any number of vendors established in a network. See also Universally Unique Identifier.
vendor-managed use control
A level of password use control in which the vendor manages compliance with the terms of the software product acquisition. See also customer-managed use control, password use control level.
See Virtual Ethernet Port Aggregator.
- In SNA, the general name for a transaction program's request for communication services.
- See people assignment criterion.
- A reserved word that expresses an action to be taken by an application programming interface (API), a compiler, or an object program. See also LU 6.2 verb.
- The text string in a business object that specifies an operation to be performed on the attributes in a business object. A business object definition contains a list of supported verbs; the business object itself contains one of the supported verbs.
The process of associating terms and phrases to elements of the business object model (BOM). See also constant.
- The process the system uses to authenticate certificate signatures.
- The process of checking to ensure that the contents of a message are correct.
- The act of confirming that a user is eligible to use a RACF-defined user ID.
- In an AIX PowerSC environment, the remote partition that determines whether a collector performed a Trusted Boot operation.
- A device that checks the correctness of transcribed data, usually by comparing it with a second transcription of the same data or by comparing a retranscription with the original data. (I) (A)
- In bar code systems, a device that measures the bars, spaces, quiet zones, and optical characteristics of a bar code symbol to determine if the symbol meets the requirements of a bar code symbology, specification, or standard.
- A change to the content of a project. Each time a project changes, for example, with the addition of new questions or categories, a new version can be generated.
- The set of properties and content associated with an instance of a document in an object store. A version is created each time a document is checked out, edited, and checked in. A document version can be designated as a major version or a minor version.
- Applications with the same ID but different validity dates.
- A separately licensed program that typically has significant new code or new function.
- An object that implements a particular revision of an element. The versions of an element are organized into a version tree structure. See also checked-out version.
- A backup copy of a file stored in server storage. The most recent backup copy of a file is the active version. Earlier copies of the same file are inactive versions. The number of versions retained by the server is determined by the copy group attributes in the management class.
- The second level in the software hierarchy, located between product and release. A product can have multiple versions, and a version have multiple releases. See also parent software, release, software hierarchy, variation.
- The referenceable state of an artifact. In a linked data system, each version can be referenced with a unique URI. See also artifact, configuration, configuration specification, revision.
- A member of a set of similar programs or packages and, in DB2 for z/OS, similar database request modules (DBRMs) or large objects (LOBs).
- In CARMA, a previous copy of a member held by an SCM system. Versions in CARMA can be created only for CARMA members. The actions available on versions depend on the SCM system that it originates from and the RAM that is used to connect to the SCM system. Some RAMs can alter versions; other RAMs make the versions read-only.
A representation of the relationship among the different versions of a virtual image depending on the criteria used when the image is checked in or imported into the reference repository.
The coordination and integration of the history of work submitted by a team. See also team support.
A resource, such as a business process model, for which multiple copies, or versions, are saved in the system. Each time a versioned resource is modified, the system saves the data as a new version so that old versions can be reverted to as needed.
version file system
See root file system.
Unique, identifying information associated with a project, document, or requirement each time it is modified. The internally generated revision number, combined with information about the author, date, time, and reason for modification, constitute version information. See also revision.
The maintenance of different versions of an uploaded file by the Files application. When a file is uploaded initially, a first version is created. When someone with editor access uploads the file again, a new version is created. All previous versions are maintained. Versions can be deleted.
versioning security template
An ACL associated with a particular document version state. Versioning security templates can define ACLs for the four possible version states: Reservation, Released, In Process, or Superseded. A versioning security template is applied through a security policy. See also application security template, template.
- The hierarchical structure in which all the versions of an element are (logically) organized. The version tree display also shows merge operations.
- A graphic representation of a versioned object that shows all branches and the versions on each branch.
See left page.
- See node.
- In graphs, a point that is the end of an arc or the intersection of multiple arcs.
Pertaining to data that is tracked within the same application and domain. See also horizontal.
The method used to distinguish one transaction flow from another within an application or group of applications. The vertical context enables Transaction Tracking to group individual transactions as part of a flow, label a node in a topology map, and link to a Tivoli Monitoring application.
vertical font size
The distance measured perpendicular to the baseline when character rotation is zero degrees. It represents the baseline-to-baseline increment that includes the vertical size of the character and the designer's recommendation for the internal leading (space above and below the character).
vertical format information
In TCP/IP, information, such as tab markers, that automatically positions lines of text with respect to other lines of text, according to defined rules. Vertical format information is usually associated with word processing.
vertical scale factor
In outline-font referencing, the specified vertical adjustment of the em square. The vertical scale factor is specified in 1440ths of an inch. When the horizontal and vertical scale factors are different, anamorphic scaling occurs. See also horizontal scale factor.
See virtual file system.
See virtual function table.
See volume group.
See VTAM Generic Resources.
- To broadcast live video to all participants in a conference.
- The broadcast of live video to all participants in a conference.
The process of dynamically inserting or combining multiple video objects into a single object for distribution. An example would be the mixing of commercials and broadcast programs for satellite distribution.
- A reusable user interface that is used for a business object or human service. A view consists of one or more other views, data bindings, layout instructions, and behavior.
- A pane or window within the IDE frame. A view can be an editor or navigator or can provide an alternate way to visualize and work with a project. A view has its own menu and may have its own toolbar.
- In Eclipse-based user interfaces, a pane that is outside the editor area, which can be used to look at or work with the resources in the workbench.
- A visual display of data represented by the model. See also graphic component, graphic view, model view controller.
- A set of attribute collections with specifications about whether those attributes are viewable, editable, or both. A view belongs to a container and can be applied when viewing entries in that container, to change the fields that can be viewed or edited. See also attribute collection, core attribute collection.
- A logical table that is based on data stored in an underlying set of tables. The data returned by a view is determined by a SELECT statement that is run on the underlying tables. See also base table, table.
- A window that displays requirements, the attributes assigned to requirements, and the relationships between requirements. See also Attribute Matrix, traceability matrix, traceability tree.
- A subset of information that can be displayed by applying filters or sorting.
- In Eclipse-based user interfaces, any pane in the workbench that is outside the editor area and can be stacked (dragged and dropped) on top of other views. Views provide different ways to look at or work with the resources in the workbench.
- In an AQL extractor, logical statements that define how to extract terms or concepts.
- A ClearCase object that provides a work area for one or more users. For each element in a VOB, a view's configuration specification selects one version from the element's version tree.
- A virtual table that is created by joining two or more tables together. Views can also include the results of calculations.
- In the CICSPlex SM web user interface, a formatted display of selected data about CICS resources or CICSPlex SM definitions. The data in a view is obtained from a query and can be presented in one or more forms. The data can be limited to a subset of CICSplex resources or definitions by establishing a context and scope.
- A dynamically controlled subset of the columns of one or more database tables. A view can give the programmer control over what information the user sees and manipulates and represents a virtual table that holds the results of a specified SELECT statement.
- The form in which an object is presented. A choice in the action bar that a user selects to look at an object from various perspectives is an example of a view.
- A representation of table data that can contain columns from one or more tables.
- The metadata that describes how the runtime system samples the tuples in a stream for visualization.
- An area within a table or chart, including rows, columns, an offspread area, and optionally a drill-through pane. It shows the data that is stored in the OLAP database.
- A pane that is outside of the editor area that can be used to look at or work with the resources in the workbench.
- In IBM ILOG JViews, the AWT or Swing component where graphic objects are displayed. To display graphic objects contained in the different layers of a grapher, you create at least one view, and often multiple views.
- A window pane, or frame, in a workspace. It may contain data from an agent in a chart or table, or it may contain a terminal session or notepad, for example. A view can be split into two separate, autonomous views. See also attribute group.
- In the CICSPlex SM API, a temporary, customized form of a resource table. A view can consist of some or all of the resource table attributes in any order.
- A defined set of tasks that are displayed in the console navigation. Views provide a way to filter the content of the navigation.
Pertaining to a mapped window whose ancestors are all mapped; not necessarily visible. Graphics requests can be performed on a window when it is not viewable, but output will not be retained unless the server is maintaining backing store.
- A vehicle that is used to display data returned from a data source. A viewer can be a spreadsheet, a word processor, or a built-in display function.
- One or more individuals who can view but not modify information.
A query plan strategy for joined queries in which one or more of the data sources is a view, by which the query optimizer incorporates the view definitions into the main query. For queries in which this technique is possible, view folding can significantly improve performance, as compared to materializing the view as a temporary table.
See eye coordinate.
In architecture, a transform that is applied to model-space coordinates. See also model transform.
In GL, a type of transformation that maps from world coordinates to viewer coordinates. The origin of the viewer coordinate system can be thought of as the location of the viewer's "eye". Viewing transformations can be used to move the "eye" around in world coordinates.
In architecture, that part of a model space that is transformed, clipped, and moved into a graphics presentation space. See also trimming.
- That portion of a partition or usable area defined for display of data to the operator. The viewport has a predefined size and position on the screen and is related to a presentation space through a specified window. See also presentation space.
- In the GDDM function, a rectangular area within the picture space that defines where the output of the current page appears on the work station.
- A rectangular area in a window on the display to view all or part of the graphic objects, depending on the zoom level.
- The viewing area on a mobile device, such as a smartphone, to view all or part of a user interface. The viewport is dependant on the zoom level and display dimensions of the mobile device.
- In BMS, that part of a screen that is allocated to a partition. See also partition.
- In GL, the last transformation in the graphics pipeline, which is used to map from normalized device coordinates to device coordinates. The viewport maps the unit cube x/w = +/-1, y/w = +/-1, z/w = +/-1 to the screen space, as measured in pixels.
view synchronous high-availability manager group
A special class of high availability (HA) group that can be created and used by components that require a certain virtual synchrony (VS) quality of service (QoS) for group communication.
See Vendor Independent Messaging.
- In Sterling Order Management, an instance of an override rule that has been violated in a transaction.
- The state of a service level agreement (SLA) when one or more service level objectives are not met. SLA violations can be used to trigger a remediation policy for affected customers.
- An act that bypasses or contravenes corporate policy.
A condition that indicates the actual measured value has not met the specified breach condition. This condition applies to a total or average type breach value. For example, if the total breach value was specified as 100, and its associated breach condition was specified as 'actual greater than supplied,' and the actual measured value was 110, then a violation is produced.
an event that is generated or triggered when a transaction performs outside of acceptable bounds (performance threshold) or fails completely (transaction status threshold). See also recovery event.
A table that holds rows that fail to satisfy the constraints and unique index requirements during data manipulation operations on base tables. See also diagnostics table.
In performance monitoring, the status of an active policy that indicates that a threshold is violated. In the hourly average view, this means the average performance time of all transactions that occurred during the hour is outside the threshold. In the instance view, the performance time of the instance is outside the threshold. See also interpreted status.
See Virtual I/O Server.
VIO storage group
See virtual input/output storage group.
See virtual IP address.
virtual address space
In virtual storage systems, the virtual storage assigned to a job, terminal user, or system task. See also address space.
- A virtual machine image with a specific application purpose that is deployed to virtualization platforms.
- A prepackaged software application that provides some well-defined business workflow, making it easier to deploy a solution with minimal configuration. Many tiers of operating systems and applications can be packaged as a single virtual appliance. See also Open Virtualization Format, virtual server collection, virtual server image.
A deployment of a standardized set of middleware and resources that is used to run specified types of workloads. Virtual applications are created with optimized patterns and offer more convenience than virtual systems by abstracting the middleware infrastructure and allowing users focus on developing applications. See also virtual application pattern, virtual system.
virtual application layer
A group of components in a virtual application pattern that facilitate complex virtual application design. A virtual application layer enables virtual application patterns to be reused in different contexts; one virtual application pattern is used as a reference layer in another virtual application pattern.
virtual application pattern
An application-centric pattern that defines the resources that are required to support virtual applications, including web applications, databases, user registries, and more. These patterns are the deployment unit for a virtual application. See also pattern, virtual application, virtual system pattern.
virtual application pattern plug-in
The resources and automation that provide the specific capabilities for a virtual application component. See also virtual application pattern type.
virtual application pattern type
A set of virtual application pattern plug-ins for a specific type of application or application capability. For example, the IBM Web Application Pattern pattern type provides the components, links, policies, and automation that are required to deploy web applications. See also virtual application pattern plug-in.
An X.25 user facility in which a call setup procedure and a call clearing procedure determine a period of communications between two DTEs in which the users' data will be transferred in the network in the packet mode of operation. All the users' data is delivered from the network in the same order in which it is received by the network. Synonym for switched virtual call.
virtual call facility
In data communication, a user facility in which a call setup procedure and a call clearing procedure determine a period of communication between two data terminal equipments (DTEs) in which user data is transferred in the network in the packet mode of operation. All user data is delivered from the network in the order it is received by the network.
The amount of storage that is available. In a thin-provisioned volume, the virtual capacity can be different from the real capacity. In a standard volume, the virtual capacity and real capacity are the same.
virtual channel connector
A connector that is used in a terminal services environment. The virtual channel connector establishes a virtual communication channel to manage the remote sessions between the Client AccessAgent component and the Server AccessAgent.
virtual channel identifier (VCI)
In asynchronous transfer mode (ATM), the locally unique numeric tag in the ATM cell header that is used to identify a virtual channel connection (VCC) within a virtual path connection (VPC). The VCI is unique only in combination with the virtual path identifier (VPI) and is defined by a 16-bit field in the ATM cell header.
virtual circuit (VC)
In a packet-switching data network, a logical end-to-end transmission channel, as opposed to a physical connection. Virtual circuits allow physical transmission facilities to be shared by many users simultaneously. See also data circuit, physical circuit.
- In information analysis, a single column or a concatenation of two or more columns that can be analyzed as if it is an existing physical data column.
- A column of information derived from an SQL statement that is not stored in the database.
virtual concurrent copy
An operation that uses SnapShot to provide a concurrent copy-like function when the source volume supports SnapShot, but not concurrent copy. Virtual concurrent copy is also referred to as CC-compatible SnapShot.
- A controller description that emulates the function of a physical controller for communication with a remote device. As an example, when a PC is attached to a system, a virtual controller must be created to allow the PC to communicate with the system.
- A controller description that is used by Advanced Peer-to-Peer Networking (APPN) and high-performance routing (HPR) support to attach and manage APPN device descriptions. This type of controller does not represent a connection to a remote station.
- A device description that does not have hardware associated with it. It is used to form a connection between a user and a physical work station attached to a remote system. A virtual device can be a virtual display station or a virtual printer.
- A device that appears to the user as a separate entity, but is actually a shared portion of a real device.
virtual device driver (VDD)
See device handler.
Virtual Ethernet Port Aggregator (VEPA)
The capability of a physical server to collaborate with an adjacent bridge to provide frame relay services between multiple virtual machines, which are located on a server and also on the external network.
virtual Fibre Channel adapter
A virtual adapter that provides client logical partitions with a Fibre Channel connection to a storage area network through the Virtual I/O Server logical partition. The framework uses N_Port ID Virtualization (NPIV) and each virtual Fibre Channel adapter has a pair of unique Worldwide Port Names (WWPNs) associated with it.
virtual function table (VFT)
In C++, an initialized table that facilitates polymorphism by indexing the addresses for the virtual functions available to a class hierarchy. The compiler creates at least one virtual function table for each class, unless the class has no virtual members.
- A stand-alone virtual environment, including operating system and binary files, that is used to define a virtual system. See also image.
- A CD or DVD image that is stored on system disks. Virtual images are stored in the integrated file system and can be in either Universal Disk Format (UDF) or ISO 9660 format.
virtual inode (v-node)
An object in a file system that represents a file. V-nodes are used to communicate between the upper half of the file system (the logical file system) and the file system implementations (such as the journaled file system, the network file system, and the CD-ROM file system).
virtual input/output storage group (VIO storage group)
A type of storage group that allocates data sets to paging storage, which simulates a direct access storage device (DASD) volume. VIO storage groups do not contain any actual DASD volumes. See also storage group.
virtual IP address (VIPA)
An IP address that is shared among multiple domain names or multiple servers. Virtual IP addressing enables one IP address to be used either when insufficient IP addresses are available or as a means to balance traffic to multiple servers.
- The substitution of virtual resources for actual resources, where the virtual resources have the same functions and external interfaces as their counterparts, but differ in attributes, such as size, performance, and cost. Virtualization is commonly applied to physical hardware resources by combining multiple physical resources into shared pools from which users receive virtual resources. See also bare metal.
- In the storage industry, a concept in which a pool of storage is created that contains several storage systems. Storage systems from various vendors can be used. The pool can be split into volumes that are visible to the host systems that use them. See also capacity licensing.
- The creation of a virtual computing resource such as an operating system, server, storage device, or network resources in a one-to-many or many-to-one association. For example, a single operating system might be divided into multiple partitions that operate as independent systems, or multiple disk devices might appear as a single logical drive. See also logical partition, partition, subcapacity.
- A technique that encapsulates the characteristics of resources from the way in which other systems interact with those resources.
- A software technology that allows multiple operating systems to run on the same processor at the same time. See also subcapacity.
A property of the on-demand operating environment that makes the best use of technology resources and minimizes complexity for users. Virtualized networks deliver computing as needed. See also grid computing.
virtual local area network (VLAN)
A logical association of switch ports based upon a set of rules or criteria, such as Medium Access Control (MAC) addresses, protocols, network address, or multicast address. This concept permits the LAN to be segmented again without requiring physical rearrangement.
- An abstract specification for a computing device that can be implemented in different ways in software and hardware.
- An instance of a data-processing system that appears to be at the exclusive disposal of a single user, but whose functions are accomplished by sharing the resources of a physical data-processing system.
- A software implementation of a machine that executes programs like a real machine.
- In z/VM, the operating system that represents the virtual processors, virtual storage, virtual devices, and virtual channel subsystem allocated to a single user. A virtual machine also includes any expanded storage dedicated to it.
Virtual Machine/System Product High Performance Option (VM/SP HPO)
An IBM-licensed program that can be installed and executed in conjunction with VM/System Product to extend the capabilities of the VM/System Product with programming enhancements, support for microcode assists, and additional functions. The VM/SP High Performance Option program package is not executable by itself. It requires installation of the VM System Product or an equivalent IBM-licensed program.
virtual member manager
A WebSphere Application Server component that provides applications with a secure facility to access basic organizational entity data such as people, logon accounts, and security roles.
- The directory or file in the file tree where another file system is mounted. For example, if /dev/hd9 is mounted on /fred, then /fred is the virtual mount point.
- A directory branch of a file system that is defined as a virtual file system. The virtual file system is backed up to its own file space on the server. The server processes the virtual mount point as a separate file system, but the client operating system does not.
Virtual Network Computing (VNC)
A graphical desktop sharing system that uses the remote frame buffer (RFB) protocol to remotely control another computer. It transmits the keyboard and mouse events from one computer to another, relaying the graphical screen updates back in the other direction, over a network.
- The node associated with a connection network when a route is calculated that goes through that connection network.
- The structure that contains information about a file system object in an virtual file system (VFS).
virtual optical device
An optical device of type 632B that supports virtual optical images. This device can be created with the Create Device Description (Optical) (CRTDEVOPT) command by using a resource name (RSRCNAME) of *VRT.
virtual path identifier (VPI)
In asynchronous transfer mode (ATM), an 8-bit field in the ATM cell header at the user-to-network interface (UNI) that indicates the virtual path connection over which a cell is to be routed.
- A view of a printer that refers only to the high-level data stream (such as ASCII or PostScript) that the printer understands. It does not include any information about how the printer hardware is attached to the host computer or the protocol used for transferring bytes of data to and from the printer.
- In System i Access, a printer attached to a host system that can receive output from a personal computer for printing. A virtual printer allows a user to use a printer attached to the host system as though the printer were directly attached to a personal computer.
virtual private network (VPN)
An extension of a company intranet over the existing framework of either a public or private network. A VPN ensures that the data that is sent between the two endpoints of its connection remains secure. See also Internet Protocol Security.
- The defined processing capacity assigned to an uncapped partition as represented to the operating system.
- A multithreaded process that makes up the database server and is similar to the hardware processors in the computer. It can serve multiple clients and, where necessary, run multiple threads to work in parallel for a single query. See also asynchronous disk I/O virtual processor.
- A setting that defines the assigned processing capacity represented to the operating system. Virtual processors represent a processing capacity less than that of a physical processor. A logical partition in the shared processor pool must have at least as many virtual processors as its assigned processing capacity.
virtual route (VR)
In SNA, either (a) a logical connection between two subarea nodes that is physically realized as a particular explicit route or (b) a logical connection that is contained wholly within a subarea node for intranode sessions. A virtual route between distinct subarea nodes imposes a transmission priority on the underlying explicit route, provides flow control through virtual route pacing, and provides data integrity through sequence numbering of path information units (PIUs). See also explicit route, path, route extension.
virtual-route-based transmission group
A transmission group that represents the virtual routes connecting the domains of the following nodes across a subarea network: (a) two interchange nodes, (b) an interchange node and a migration data host, or (c) two migration data hosts.
virtual route identifier (VRID)
In SNA, a virtual route number and a transmission priority number that, when combined with the subarea addresses for the subareas at each end of a route, identify the virtual route.
virtual route pacing (VR pacing)
In SNA, a flow control technique used by the virtual route control component of path control at each end of a virtual route to control the rate at which path information units (PIUs) flow over the virtual route. VR pacing can be adjusted according to traffic congestion in any of the nodes along the route. See also session-level pacing.
virtual route pacing response (VRPRS)
A nonsequenced, supervisory path information unit (PIU) that flows at network priority. It can overtake VR-sequenced PIUs and consists of a transmission header with no basic information unit (BIU) data.
virtual SCSI (VSCSI)
A SCSI that is based on a client and server relationship. The Virtual I/O Server owns the physical resources and acts as server, or target, device. Physical adapters with attached disks on the Virtual I/O Server partition might be shared by one or more partitions. These partitions contain a virtual SCSI client adapter that recognizes these virtual devices as standard SCSI-compliant devices and LUNs. See also Virtual I/O Server.
virtual SCSI client adapter
A virtual adapter in one logical partition that communicates with a virtual SCSI server adapter in another partition. A virtual SCSI client adapter allows a logical partition to access a storage device being made available by another logical partition. See also virtual SCSI server adapter.
virtual SCSI server adapter
An adapter in one logical partition that is available to a virtual SCSI client adapter in another logical partition. A logical partition to which a storage device is assigned can map that device to a virtual SCSI server adapter. See also virtual SCSI client adapter.
A sensor that relays information on the site attributes, such as the physical dimensions of a zone. Dimensions of the coordinates, width, length, or height can be noted. These dimensions are assigned to a particular zone.
- The logical service point that Content Platform Engine clients interact with. A virtual server can map to a single independent server instance or to a set of server instances. A client issues a request to a virtual server and one server instance responds. See also server instance.
- A server that shares its resources with other servers to support applications.
- A system composed of partitioned, shared, or virtualized resources presented from a host system. An operating system and other software can be installed on a virtual server. See also logical partition.
- A logical construct that appears to comprise processor, memory, and I/O resources conforming to a particular architecture. A virtual server can support an operating system, associated middleware, and applications.
virtual server collection
A set of virtual servers that are involved in supporting a workload. The set is not necessarily static. The constituents of the collection at any given point are determined by the virtual servers involved in supporting the workload at that time. See also Open Virtualization Format, virtual appliance, virtual server image.
virtual server image
A package containing metadata that describes the system requirements, virtual disks, and any goals and constraints for the virtual machine, such as isolation and availability. See also virtual appliance, virtual server collection.
virtual server network (VSN)
The capability that provides enhanced access, security control, and integrated management for interconnected storage and virtual servers, and for interconnected fabrics, such as virtual switches and routers.
- A set of definitions that provides configuration defaults for z/VM virtual servers. z/VM Center uses virtual server templates to create z/VM virtual servers.
- The template on which a virtual server is based. The virtual server is allocated using the hardware requirements of the template.
virtual service processor (VSP)
The firmware that controls the powering on and powering off of a logical partition, including loading the firmware that controls the I/O slots and initializing the memory space of the logical partition.
Virtual Shared Disk
See IBM Virtual Shared Disk.
virtual storage (VS)
The storage space that can be regarded as addressable main storage by the user of a computer system in which virtual addresses are mapped to real addresses. The size of virtual storage is limited by the addressing scheme of the computer system and by the amount of available auxiliary storage, not by the actual number of main storage locations. See also storage.
Virtual Storage Access Method (VSAM)
An access method for direct or sequential processing of fixed-length and variable-length records on disk devices. The records in a VSAM data set or file can be organized in logical sequence by a key field (key sequence), in the physical sequence in which they are written on the data set or file (entry sequence), or by relative-record number.
Virtual Storage Extended (VSE)
A system that consists of a basic operating system (VSE/Advanced Functions), and any IBM supplied and user-written programs required to meet the data processing needs of a user. VSE and the hardware that it controls form a complete computing system. Its current version is called VSE/ESA.
Virtual Storage Extended/Enterprise Systems Architecture (VSE/ESA)
The VSE operating system operating in an ESA environment. ESA is an extension to the System/370 architecture and includes an advanced addressability feature that provides access registers.
Virtual Storage Option (VSO)
An option for data entry database (DEDB) areas that maps an area into a data space or a coupling facility structure when the area is opened. The share level of the database determines which is used. Any VSO area control interval (CI) or coupling facility structure that has been loaded into a data space is subsequently read from the data space or coupling facility structure rather than from DASD.
- A collection of virtual machines.
- A deployment of a flexible set of middleware and resources that is used to define editable application environments. Virtual systems are created with customized topologies and offer more control than virtual applications by allowing users to configure middleware and tune OS settings. See also virtual application, virtual system pattern.
virtual system pattern
One or more middleware-centric virtual images, which can include script packages, that implement a deployment topology. A virtual system pattern is a shared topology definition used for repeatable deployment. See also pattern, virtual application pattern, virtual system.
- A table created to access data in an external file, external DBMS, smart large object, or in the result set of an iterator function in a query. The database server does not manage external data or directly manipulate data within a smart large object. The Virtual-Table Interface allows users to access the external data in a virtual table using SQL DML statements and join the external data with Informix table data.
- A table or view where the rows are derived as they are required in memory.
Virtual Tape Server (VTS)
An enterprise virtual tape system that combines high-speed disk access with low-cost tape storage by virtualizing data in a disk cache buffer. Storage management routines efficiently utilize tape cartridge capacity which reduces the number of required tape cartridges.
- A software implementation of the Trusted Platform Module specification that is described by the Trusted Computing Group. The PowerSC Trusted Boot feature provides virtual TPM functions for virtual machines running the AIX operating system with the PowerVM hypervisor on Power Systems servers.
- A software implementation of the Trusted Platform Module specification that is described by the Trusted Computing Group. The Trusted Platform Module is implemented as a physical chip on systems.
- A tape volume that resides in a tape volume cache of a virtual tape server (VTS). Whether the volume resides in the tape volume cache as a virtual volume or on a stacked volume as a logical volume (LVOL) is transparent to the host.
- An archive file on a target server that represents a sequential media volume to a source server.
A program that can change other programs to include a copy of itself. The other programs are then said to be infected by the virus. Additionally, the virus can perform other operations that can take up system resources or destroy data.
- In a user interface, the property of a control that declares whether the control is to be displayed or not displayed during run time.
- In architecture, the property of a segment that declares whether the part of a picture defined by the segment is to be displayed or not displayed during the drawing process.
visible data node
A parent data node that is represented by a row in a Gantt or Schedule chart. The application user can only see the row if the display area is large enough. A visible data node has all its ancestors expanded.
An intelligent pattern-recognition system that consists of a camera and lamps mounted on the gripper assemblies, the vision system controller, and the vision monitor. The vision system scans the external labels on cartridges to provide positive cartridge identification.
The process of tracking unique visitors across single or multiple visits to a web application. Using Tealeaf technologies, each visitor to a web application can be uniquely and permanently identified, which assists in longer-term study of customer experience and issues.
visual data stream (VDS)
In bidirectional text representation, a stream of data that is organized in the sequence in which the data is presented on the screen. See also logical data stream.
A tool that lets database administrators and application programmers use a graphical interface to display and analyze detailed information on the access plan of a given SQL or XQuery statement. The tasks provided by this tool can be accessed from the Control Center.
- An association between a Scalable Vector Graphics (SVG) diagram and the set of actions that describe how the diagram should be updated based on the values of metrics or key performance indicators (KPIs).
- A graph, chart, plot, table, map, or any other visual representation of data. A single visualization might also contain multiple graphs, charts, plots, and so on.
See VTAM internal trace.
vital record processing
The process of inventory management that determines which data sets and volumes DFSMSrmm should retain and whether a volume should be moved. These volumes and data sets have been assigned a vital record specification. See also inventory management, storage-location management processing.
A data set or volume maintained to meet an externally-imposed retention requirement, such as a legal requirement. Compare with disaster recovery. See also disaster recovery.
vital record specification (VRS)
In DFSMSrmm, policies defined to manage the retention and movement of data sets and volumes for disaster recovery and vital records purposes. See also primary vital-record specification, secondary vital-record specification.
See Visualization Markup Language.
See virtual local area network.
The process of adding a VLAN number to the Ethernet packet to logically segment a physical network, thereby restricting the network layer 2 connectivity to the members who belong to the same VLAN.
See virtual lookaside facility.
See Vertical Licensed Internal Code.
See virtual logical unit number.
See variable-length variable blocked.
See virtual machine.
A function of the Communications Utilities for i5/OS licensed program that provides distribution services between an i5/OS SNADS network and both a VM Remote Spooling Communications Subsystem (RSCS) network and a Multiple Virtual Storage/Job Entry Subsystem (MVS/JES) network.
See Virtual Machine/System Product.
See Virtual Machine/System Product High Performance Option.
See Virtual Machine/Extended Architecture.
See Virtual Network Computing.
See virtual node.
See virtual inode.
See virtual origin.
See versioned object base.
- The set of terms and phrases that are used for rule editing.
- A list of words with which DirectTalk matches input spoken by a caller.
- A repository for storing reusable business elements, such as terms, business item definitions, roles, messages, and errors, that are used in a business process.
A list of voice segments identified by a group ID. Voice directories can be referenced by prompts and state tables. See also voice table.
In voice mail, a recording made by a caller for later retrieval by a subscriber. See also greeting.
The capability to record, play back, distribute, route, and manage voice recordings of telephone calls through the use of a processor, without the intervention of agents other than the callers and the message recipients.
- Hardware and software used to answer incoming calls by playing one or more prerecorded messages.
- A telephony device that uses prerecorded voice responses to provide information in response to dual-tone multifrequency (DTMF) or voice input from a telephone caller.
A grouping of voice segments used for organizational purposes. Voice tables can be referenced by prompts, but not by state tables. See also voice directory.
See Voice over Internet Protocol.
A table whose cardinality can vary significantly over relatively short periods of time. Compared to statistics that are collected for non-volatile tables, statistics that are collected for volatile tables are less likely to represent the actual data in the tables. The optimizer takes this situation into account when determining access plans involving a volatile table.
See volume serial number.
- A fixed amount of physical or virtual storage on a data storage medium.
- A logical subdivision of a record folder into smaller and more easily managed units. A volume has no existence independent of the folder.
- The representation of an Small Computer System Interface (SCSI) disk that is presented to a host system. See also thin provisioning.
- A discrete unit of storage on disk, tape or other data recording medium that supports some form of identifier and parameter list, such as a volume label or input/output control. See also scratch volume, server storage, storage pool, storage pool volume, unassociated volume.
See blanket contract.
volume full threshold
A value that indicates when a volume should be marked as full. This threshold specifies a number of free KB for the volume; when the number falls below this threshold, the volume is marked full.
volume history file
A file that contains information about volumes that have been used by the server for database backups and for export of administrator, node, policy, or server data. The file also has information about sequential-access storage pool volumes that have been added, reused, or deleted. The information is a copy of volume information that is recorded in the server database.
volume mount analyzer
A program that assists in the analysis of the current tape environment, allowing identification of the most desirable data sets for redirection to the direct access storage device (DASD) buffer for management using storage management subsystem (SMS) facilities.
A record containing information related to a volume, such as volume serial number (VOLSER), library name, and storage group. The volume record resides within the tape configuration database (TCDB).
See consistency group.
Volume Shadow Copy Service (VSS)
A set of Microsoft application-programming interfaces (APIs) that are used to create shadow copy backups of volumes, exact copies of files, including all open files, and so on.
Statistical information about the activity on a tape, diskette, or cartridge volume including statistics about the session (such as the number of read, write, and retry operations), and lifetime (accumulated) statistics (such as the number of read and write errors and the number of bytes read and written).
In the storage management subsystem (SMS), an indicator of the availability of a volume for system management: the volume is not ready for system management because it contains data sets that are ineligible for system management; the volume is ready for system management because all of the data sets on a volume have an associated storage class and are cataloged in an integrated catalog facility (ICF) catalog; the volume will not be managed by the system because it contains no system-managed data sets and has not been initialized as system-managed. See also physical volume status.
- A table on a direct access volume that describes the location, size and other characteristics of each data set on the volume. Each entry is a data set control block (DSCB).
- An area on a disk or diskette that describes the location, size, and other characteristics of each file, library, and folder on the disk or diskette.
A region on the surface of the Earth that has boundaries with neighboring regions. The boundaries are defined by the geodesic distances between the center point of the Voronoi cell and the center points of its neighbors. A Voronoi cell consists of all points that are closer to the center of the Voronoi cell than to the center of any other Voronoi cell.
Voronoi cell structure
A subdivision of the surface of the Earth into cells where every point within a particular cell is closer to the center point of that cell than to the center point of any other cell.
In the two-phase commit protocol, the response of an agent to the request of the initiator. The application transaction program uses the responses to determine if it should commit or roll back its protected resources.
The response, to a Prepare presentation services header with a Forget presentation services header, by the agent when no changes have been made to the resources, for the optimization of the two-phase commit flows.
See valid printable area.
A component consisting of a base card, which connects to the digital trunk adapter in the RS/6000, and a trunk interface card (TIC), which manages the trunk connection to the switch. The single digital trunk processor contains one VPACK, and the multiple digital trunk processor contains slots for up to five VPACKs. See also SPACK, XPACK.
See data path device.
See virtual path connection.
See vital product data.
See virtual path identifier.
See Voice Protocol for Internet Messaging.
See virtual private network.
See virtual route.
See virtual route identifier.
See voltage regulator module.
See virtual routing node.
See voted read-only.
See virtual route pacing.
See virtual route pacing response.
See vital record specification.
See voice response unit.
See Virtual Storage Access Method.
A special key-sequenced data set (KSDS) with an index containing extensive data set and volume information that the Virtual Storage Access Method (VSAM) requires to locate data sets or files, allocate and deallocate storage space, verify the authorization of a program or operator to gain access to a file, and accumulate usage statistics for data sets or files. VSAM catalogs have been functionally replaced by integrated catalog facility (ICF) catalogs. VSAM catalogs are not supported by z/OS.
VSAM record-level sharing (VSAM RLS)
An extension to the Virtual Storage Access Method (VSAM) that provides direct record-level sharing of VSAM data sets from multiple address spaces across multiple systems. Record-level sharing uses the z/OS Coupling Facility (CF) to provide cross-system locking, local buffer invalidation, and cross-system data caching. Contrast with global shared resources and local shared resources. See also global shared resource, local shared resource, SMSVSAM.
See VSAM record-level sharing.
VSAM volume control record (VVCR)
The first logical record in the VSAM volume data set (VVDS) that contains information to manage direct access storage device (DASD) space and the basic catalog structure (BCS) back pointers.
VSAM volume data set (VVDS)
A data set that describes the characteristics of the Virtual Storage Access Method (VSAM) and system-managed data sets residing on a given direct access storage device (DASD) volume. A VVDS is part of an integrated catalog facility (ICF) catalog. See also basic catalog structure, integrated catalog facility catalog.
See virtual storage area network.
See virtual SCSI.
See Virtual Storage Extended.
See Virtual Storage Extended/Advanced Functions.
See Virtual Storage Extended/Advanced Functions.
See Virtual Storage Extended/System Product.
See VSAM shared information.
See virtual server network.
See Virtual Storage Option.
See virtual service processor.
A backup operation that uses Microsoft Volume Shadow Copy Service (VSS) technology. The backup operation produces an online snapshot (point-in-time consistent copy) of Microsoft Exchange data. This copy can be stored on local shadow volumes or on Tivoli Storage Manager server storage.
VSS Fast Restore
An operation that restores data from a local snapshot. The snapshot is the VSS backup that resides on a local shadow volume. The restore operation retrieves the data by using a file-level copy method.
VSS Instant Restore
An operation that restores data from a local snapshot. The snapshot is the VSS backup that resides on a local shadow volume. The restore operation retrieves the data by using a hardware assisted restore method (for example, a FlashCopy operation).
VSS offloaded backup
A backup operation that uses a Microsoft Volume Shadow Copy Service (VSS) hardware provider (installed on an alternate system) to move IBM Data Protection for Microsoft Exchange data to the Tivoli Storage Manager server. This type of backup operation shifts the backup load from the production system to another system.
A function that uses a Microsoft Volume Shadow Copy Service (VSS) software provider to restore VSS Backups (IBM Data Protection for Microsoft Exchange database files and log files) that reside on Tivoli Storage Manager server storage to their original location.
See VSAM work area.
VT100 workstation protocol
i5/OS support for the VT100 work station protocol that allows a user to access, using TELNET VT100 client support, VT100 application programs on other systems in a TCP/IP network. Users on other systems with a TELNET VT100 client emulation package are able to access i5/OS application programs through the i5/OS TELNET VT100 server.
VT220 workstation protocol
i5/OS support for the VT220 work station protocol that allows a user to access, using TELNET VT220 client support, VT220 application programs on other systems in a TCP/IP network. Users on other systems with a TELNET VT220 client emulation package are able to access i5/OS application programs through the i5/OS TELNET VT220 server.
See Virtual Telecommunications Access Method.
VTAM Terminal Block (VTCB)
An IMS control block that represents a VTAM terminal, both static and dynamic. The VTCB contains the following IMS control blocks and data areas: CLB, CTB, CRB, CIB, DDM work area, and CTT.
See VTAM Terminal Block.
See virtual terminal manager.
See virtual terminal manager/function manager.
See volume table of contents.
See Virtual Trusted Platform Module.
See Virtual Tape Server.
See value unit.
See value unit exhibit.
See value unit exhibit.
See VSAM volume control record.
See VSAM volume data set.
See VSAM volume record.
See variable workload license charge.