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DAA: See designated approving authority.
daemon: A program that runs unattended to perform continuous or periodic functions, such as network control.
DAF: See destination address field. See also origin address field.
damaged logical unit of work: The effect on protected resources caused by part of the resources committing and part rolling back.
DAP: See directory access protocol.
DARPA: See Defense Advanced Research Projects Agency.
DASD: See direct access storage device. See also random access memory.
data area: A system object used to communicate data, such as CL variable values between the programs within a job and between jobs. The system-recognized identifier for the data area is *DTAARA.
data authority: A specific authority to read, add, update, or delete data, to run a program, or to search a library or directory.
database (DB): A collection of interrelated or independent data items that are stored together to serve one or more applications.
database administrator (DBA): A person who is responsible for the design, development, operation, security, maintenance, and use of a database.
database file: One of several types of the system object type *FILE kept in the system that contains descriptions of how input data is to be presented to a program from internal storage and how output data is to be presented to internal storage from a program.
database management system (DBMS): See also data server. See database manager.
database manager: A program that manages data by providing centralized control, data independence, and complex physical structures for efficient access, integrity, recovery, concurrency control, privacy, and security. See also data server.
database reference field: In the Data Description Specifications Design Utility (DSU), a field in a data description specifications (DDS) source file that is created by referring to the description of an existing field in a database file.
data bean: A type of bean that is placed in a JSP file. Data beans can have associated commands that are invoked when the JSP file instantiates the data bean at run time.
data cache unit (DCU): A high-speed buffer storage that contains frequently accessed instructions and data to reduce access time.
data character set: See character set.
data circuit-terminating equipment (DCE): The equipment that provides signal conversion and coding between the data terminal equipment (DTE) and the line. The DCE provides all the functions required to establish, maintain, and end a connection.
data clause: In COBOL, a clause in a data description entry in the Data Division that describes a particular characteristic of a data item.
data code page: In Network File System (NFS), a list of the data name components of the files that are exported to and mounted on the specified NFS client or netgroup.
data communication: Transfer of data among functional units by means of data transmission protocols.
data compression: The reduction of data volume on the media when performing save operations.
data confidentiality: A function of the system that prevents unauthorized disclosure of data.
data conversion: The process of changing data from one form of representation to another.; The process of changing from one coded character set identifier (CCSID) to another. A system does data conversion when exchanging data with another system that is using a different CCSID.
data country code (DCC): A 3-digit code, unique to each country or region, that specifies the X.21 call format used by a network in its International Data Number to call another station. See also data network identification code.
data decompression: Reconstruction of data from a compressed format when performing a restore operation.
data definition (DD): In IDDU, information that describes the contents and characteristics of a field, record, or file.; A program statement that describes the features of, specifies relationships of, or establishes the context of data. A data definition reserves storage and can provide an initial value.
Data Definition Language (DDL): A language for describing data and its relationships in a database.
data description entry: In COBOL, an entry in the Data Division that describes the characteristics of a data item.
data description specifications (DDS): A fixed format for describing and creating IBM® i databases or device files.
Data Description Specifications Design Utility (DSU): A feature of the CoOperative Development Environment/400 licensed program that helps users develop and create display files, printer files, and database files.
data dictionary: In IDDU, an object for storing field, record format, and file definitions. The system-recognized identifier for the object type is *DTADCT.
data division: One of the four main parts of a COBOL program. The data division describes the files to be used in the program and the records contained within the files. It also describes any internal working storage records that are needed.
data dump: In COBOL, the contents of the data areas used by a program that has failed.
data-encrypting key: A key that is used to encipher, decipher, or authenticate data. See also key-encrypting key.
Data Encryption Algorithm (DEA): In Cryptographic Support, the equivalent to the Data Encryption Standard.
Data Encryption Standard (DES): A cryptographic algorithm designed to encrypt and decrypt data using a private key.
data file: In RJE, a remote job input stream that can contain host system commands and job control language as well as data.; A group of related data records organized in a specific order. A data file can be created by the specification of FILETYPE(*DATA) on the create commands. See also command file, source file.
data file utility (DFU): The part of the Application Development ToolSet feature that is used to enter, maintain, and display records in a database file.
data flow control layer (DFC layer): In SNA, the layer within a half-session that (a) controls whether the half-session can send or receive, or both send and receive request units (RUs) at the same time, (b) combines related RUs into RU chains, (c) defines the limits of transactions by using the bracket protocol, (d) controls the connection of requests and responses in accordance with control modes specified when the session is started, (e) creates sequence numbers, and (f) associates requests with responses.
datagram: A form of asynchronous messaging in which an application sends a message, but does not require a response.
data group: In Business Graphics Utility, a collection of values that identify the comparisons in a chart. For example, the relative size of the slices in a pie chart or the relative height of the bars in a bar chart. See also data value.; In the GDDM function, a collection of data values displayed, for example, as a pie chart or as the plotted points on a line of a line chart. More than one data group may be displayed on a chart.
data hierarchy: In COBOL, the relationship between a group item or record and the group data items and elementary data items that make it up.
data integrity: The condition that exists as long as accidental or intentional destruction, alteration, or loss of data does not occur.
data interchange: The use of data by systems of different manufacture.
data interchange format (DIF): In System i® Access, a format that presents data in rows and columns.
data item: In COBOL, a character or a set of consecutive characters (excluding literals in either case) defined as a unit of data by the COBOL program.; A unit of information to be processed.
data label: In Business Graphics Utility and the GDDM function, a text string that describes a set of data values. Data labels are used with bar charts, pie charts, and Venn diagrams.
data line: In the GDDM function, a line drawn parallel to a chart axis, through a specified value along the other axis.; In Business Graphics Utility, a straight line drawn from either axis that shows the exact data values on the chart.
datalink: A field in a database file that contains a link to an object. The link is in the form of a uniform resource locator (URL).
data link: The physical connection (communications lines, modems, controller, work stations, other communications equipment), and the rules (protocols) for sending and receiving data between two or more locations in a data network.
data link connection identifier (DLCI): The field in a Q.922 frame that is used for frame relay routing. Each DLCI identifies a frame relay virtual circuit.
data link control layer (DLC layer): In communications, the layer that consists of the link stations that schedule data transfer over a link between two nodes and perform error control for the link. Examples of data link control are SDLC and HDLC. See also data flow control layer.
data link control protocol (DLC): The protocol layer used by nodes on a data link to accomplish an orderly exchange of information.
data link escape character (DLE, DLE character): In binary synchronous communication (BSC), a transmission control character used to indicate that the next character is a control character, not a data character.
DataLink File Manager: A system function that maintains the status of objects that are linked to a database file through a datalink.
data link layer: In the Open Systems Interconnection reference model, the layer that provides services to transfer data between entities in the network layer over a communication link. The data link layer detects and possibly corrects errors that may occur in the physical layer.
data link protocol: The rules that govern control of the physical connection for sending and receiving data between two or more locations in a network. Examples of data link protocols include (a) asynchronous, (b) binary synchronous communications (BSC), (c) Ethernet, (d) synchronous data link control (SDLC), (e) token-ring network, and (f) X.25. See also communications line.
data management: The part of the operating system that controls the storing and accessing of data to or from an application program. The data can be on internal storage (for example, database), on external media (, tape, or printer), or on another system.
data mapping: The process of changing characters from one form of representation to another, such as from zoned decimal to packed decimal.
data migration: The movement of data when the software is upgraded or the data is transferred to a different hardware server or model.
data mode: In data communications, a time during which BSC is sending or receiving characters on the communications line.
data multiplexer: See multiplexed device.
data name: In COBOL, a user-defined word that names a data item. When used in the general formats, data name represents a word that cannot be subscripted, indexed, or qualified unless specifically permitted by the rules of that format. See also identifier.
data network identification code (DNIC): A 4-digit code that specifies the X.21 call format used by a network in its International Data Number to call another station. The first three numbers are the data country or region code, and the last number is the country or region network identifier. See also data country code.
data object: An object that conveys information, such as text, graphics, audio, or video. See also machine object.; A program variable that provides operational and possibly representational characteristics to byte strings in spaces.
data origin authentication: The confirmation that data comes from the apparent originator.
Dataphone digital service (DDS): The AT&T line service that allows the customer to transmit data on the line in a digital format.
data pointer: A pointer that provides addressability and scalar representational attributes to a byte string in a space.
data policy: The collection of protocols that governs Phase II negotiations.
data queue: An object that is used to communicate and store data used by several programs in a job or between jobs. The system-recognized identifier is *DTAQ.
data reference line: In the GDDM function, a data line that also acts as a shading boundary for the first data group of a surface chart, histogram, or composite bar chart, or for all the data groups of a multiple bar chart. If no data reference line is present, such data groups are shaded from the horizontal axis.
data server: A device on a local area network (LAN) that provides services, data, or facilities for other devices on the network.
data service unit (DSU): A device that provides a digital data service interface directly to the data terminal equipment. The DSU provides loop equalization, remote and local testing capabilities, and a standard EIA/CCITT interface.
data stream: The commands, control codes, data, or structured fields that are transmitted between an application program and a device such as printer or nonprogrammable display station.
data structure: In Open Source Initiative (OSI), the syntactic structure of symbolic expressions and their storage allocation characteristics.; An area of storage that defines the layout of the fields, called subfields, within the area. A data structure is program described.
data terminal equipment (DTE): A device on a data link that sends and receives data, and provides data communications control functions according to protocols.; In OSI, a physical node on a network.
data token: In OSI, the token that controls which peer entity has permission to send on a half-duplex connection.
data tower: In AFP Utilities, a set of Intelligent Printer Data Stream commands that represent a data type, such as text, image, graphics, and bar code.
data traffic: In data communications, the quantity of data transmitted past a particular point in a path.
data type: In programming languages, a set of values together with a set of permitted operations. A data type determines the kind of value that a variable can assume or that a function can return.; An attribute used for defining data as either numeric or character.; In SQL, an attribute of columns, literals, host variables, special registers, parameters, and the results of functions and expressions.; In OSI, a category of data clearly defined using a data declaration method, such as ASN.1 or Pascal.
data value: In Business Graphics Utility, a single, numeric data item entered as a value for a horizontal line or vertical line. See also data group.
data warehousing: A set of hardware and software components that can be used to analyze large amounts of data for making effective business decisions. For example, data warehousing can be used to analyze daily sales information, customer orders, products, inventory, and schedules.
date: A three-part value that designates a day, month, and year: for example, YYYY-MM-DD.
date duration: A DECIMAL(8,0) value that represents a number of years, months, and days in the format yyyymmdd.
datetime value: A value of the data type DATE, TIME, or TIMESTAMP.
DB: See database.
dB: See decibel.
DB2® for IBM i: The integrated relational database manager on the system. It provides access to and protection for data. It also provides advanced functions such as referential integrity and parallel database processing.
DB2 Query Manager (Query Manager): Part of the DB2 Query Manager and SQL Development Kit for IBM i licensed program that is a collection of tools used to obtain information from the DB2 for IBM i database. DB2 Query Manager can also be used to create query definitions, to run new or existing query definitions, or to format query information.
DB2 Query Manager and SQL Development Kit for IBM i: The IBM licensed program that is one of the DB2 family of products. Query Manager allows users to develop SQL queries and reports. The SQL Development Kit allows programmers to develop SQL applications.
DBA: See database administrator.
DBCLOB: See double-byte character large object.
DBCS: See double-byte character set. See also single-byte character set, multibyte character set.
DBCS code: The hexadecimal code, 2 bytes in length, that identifies a double-byte character.
DBCS conversion: A function of the operating system that allows a display station user to enter alphanumeric data and request that the alphanumeric data be converted to double-byte data.
DBCS conversion dictionary: A table used by the conversion function to map alphanumeric entries to double-byte entries. The system-recognized identifier for the object type is *IGCDCT.
DBCS data: In DB2 for IBM i, data that is associated with a double-byte character set.
DBCS-either: Pertaining to a character string that is either SBCS or bracketed DBCS, but not both. See also DBCS-graphic, DBCS-open, DBCS-only.
DBCS font file: A system-supplied file that holds the 24x24 character images of one of the following groups of commonly used characters: 1) Japanese non-Kanji and basic-Kanji, 2) Korean non-Hangeul/non-Hanja, Hangeul, and a subset of Hanja, 3) Traditional Chinese non-Chinese and a subset of primary Chinese characters, or 4) all IBM-defined Simplified Chinese characters.
DBCS font table: A system-supplied table that holds either 24x24 or 32x32 pel character images of a double-byte character set. A Japanese 24x24 DBCS font table holds Japanese extended Kanji and user-defined characters. A Korean 24x24 DBCS font table holds a subset of Hanja and user-defined characters. A Traditional Chinese 24x24 DBCS font table holds a subset of primary Traditional Chinese, all secondary Chinese, and user-defined characters. A Simplified Chinese 24x24 DBCS font table holds IBM-supplied Simplified Chinese characters as well as user-defined characters. A 32x32 DBCS font table holds 32x32 pel character images of a double-byte character set, including its user-defined characters. The system-recognized identifier for the object type is *IGCTBL.
DBCS-graphic: Pertaining to a character string in which each character is represented by 2 bytes. Used only with the EBCDIC encoding scheme. The character string does not contain shift-out (SO) and shift-in (SI) characters. See also DBCS-either, DBCS-open, DBCS-only.
DBCS number: The decimal value, 5 digits in length, that identifies a double-byte character.
DBCS-only: Pertaining to a character string that is only bracketed DBCS. See also DBCS-either, DBCS-graphic, DBCS-open, graphic data type.
DBCS-open: Pertaining to a character string that can be a mixture of SBCS and bracketed DBCS. See also DBCS-either, DBCS-graphic, DBCS-only.
DBCS sort table: A system-supplied object that contains sequencing information to sort double-byte characters. The system-recognized identifier for the object type is *IGCSRT.
DBMS: See database management system. See also data server.
DCA: See Document Content Architecture.
DCC: See data country code. See also data network identification code.
DCE: See data circuit-terminating equipment.
D-channel: See delta channel. See also bearer channel.
DCM: See Digital Certificate Manager.
DCT: See destination control table.
DCU: See data cache unit.
DD: See data definition.; See device driver.
DDE: See dynamic data exchange.
DDE client: The computer, or an application running on it, that provides the function of receiving dynamic data exchange (DDE) data from another DDE-enabled application.
DDE server: The computer, or an application running on it, that provides dynamic data exchange (DDE) data to another DDE-enabled application. In VisualAge® RPG, all components provide DDE server functions.
DDI: See distributed data interface.
DDL: See Data Definition Language.
DDM: See distributed data management.
DDM Architecture: See Distributed Data Management Architecture.
DDM file: A system object with type *FILE, created by a user on the local (source) system, that identifies a data file that is kept on a remote (target) system. The DDM file provides the information needed for a local system to locate a remote system and to access the data in the remote data file.
DDN: See Defense Data Network.
DDS: See data description specifications.; See Dataphone digital service.
DDSA: See digital data service adapter.
DEA: See Data Encryption Algorithm.
dead-letter queue: A queue to which a queue manager or application sends messages that cannot be delivered to their correct destination.
deadlock: Unresolved contention for the use of resources.
deallocate: To release a resource that is assigned to a specific task.
debug: To detect, diagnose, and eliminate errors in programs.
debugger: A tool used to detect and trace errors in computer programs.
debugging line: A COBOL statement run only when the WITH DEBUGGING MODE clause is specified. Debugging lines can help determine the cause of an error.; In COBOL, any line with a D in the indicator area of the line.
debugging section: In COBOL, a declaratives section that receives control when an identifier, file name, or procedure name is encountered in the Procedure Division.
debug mode: An environment in which programs can be tested.; A mode in which a program provides detailed output about its activities to aid a user in detecting and correcting errors in the program itself or in the configuration of the program or system.
decibel (dB): A unit of signal strength or loudness, such as the signal on a data communications channel.
decimal floating-point number: A 64-bit or 128-bit representation of a number with a precision of 16 or 34 decimal digits and an exponent. Decimal floating-point numbers include normal numbers and subnormal numbers as well as the special values of infinity, NaN, and sNaN. See also not-a-number, infinity.
decimalization table: In Cryptographic Support, a table of 16 decimal characters that is used to convert a hexadecimal value to a decimal value. Each hexadecimal digit is used as an offset in the (decimalization) table and is replaced with the value found there.
decimal position: The location of the decimal point in a series of numbers.; Numbers to the right of the decimal point. For example, 4.009 has three decimal positions.
declaration: In the C and C++ languages, a description that makes an external object or function available to a function or a block statement.; In Java™ programming, a statement that establishes an identifier and associates attributes with it, without necessarily reserving its storage or providing the implementation. (Sun)
declaratives: In COBOL, a set of one or more special-purpose sections, at the beginning of the Procedure Division that can be used for error checking or debugging.
declarative sentence: In COBOL, a compiler-directing statement that specifies when a debugging section or an exception/error procedure is to be run.
decompression: A function that exchanges control characters for actual data.
decrypt: To decipher data.; In Cryptographic Support, to convert ciphertext into plaintext. See also encrypt.
decryption: In computer security, the process of transforming encoded text or ciphertext into plaintext.
dedicated line: A connection not requiring dialing to establish communication.
dedicated save operation: An operation that the user runs to save objects when no other jobs are running. See also save-while-active operation.
Dedicated Server for Domino® (DSD): A System i server that is specially designed to run Lotus® Domino servers and applications.
dedicated service tools (DST): Service functions that are available only from the console and can run when the operating system is not available, as well as when the operating system is available.; The part of the service function used to service the system when the operating system is not running.
dedicated system: A system intentionally reserved for a single job or task.
de-editing: In COBOL, the logical removal of all editing characters from a numeric edited data item to determine the unedited numeric value of the item.
default: Pertaining to an attribute, value, or option that is assumed when none is explicitly specified.
default configuration: In OSI, the set of default configuration and initialization values supplied with OSI Communications Subsystem. The user can change the default configuration, which is provided by initial records supplied in the subsystem information base shipped with OSI Communications Subsystem.
default delivery: The method of delivering messages to a message queue without interrupting the job, and sending the system-assigned reply for any messages requiring a reply. Messages are placed on the message queue only if the message queue is QSYSOPR; otherwise, the messages are discarded by the system. For messages requiring a reply, replies are sent before the messages are discarded.
default entry point: An entry point in a user's program that receives control from the operating system when a user runs an application.
default error handler: The part of the RPG logic cycle that handles program or file exceptions/errors when program or file exceptions/errors are not controlled by the programmer.
default focal point: In SNA, a network node that receives alerts from nodes that do not have defined focal points. See also primary focal point.
default form: A temporary object that contains the description of the format of a printed or displayed report, which was built without explicitly specifying a form to be applied against it.
default network message queue: A message queue to which messages related to network activity are sent when either the user profile does not have a message queue specified or the message queue named in the user profile cannot be used.
default network output queue: An output queue to which spooled files are sent when either the user does not have an output queue specified or the output queue name in the user profile cannot be used.
default password: A password that is the same as the service tools user ID. For example, the IBM-supplied QSECOFR service tools user ID is shipped with a default password of QSECOFR.
default printer: A printer that is assigned to a system or user and accepts all the printed output from that system or user, if no other printer is specified.
default profile: The profile that is assigned ownership of an object if the original owning profile is deleted or damaged.
default program: A user-specified program that is assumed when no other program is specifically named on a debug command, or a user-defined program for handling error messages.
default record: A record that consists entirely of default values (numeric fields are filled with zeros; character fields are filled with blanks; and fields of either data type (numeric or character) can be filled with a value specified by the user with the DFT keyword in DDS).
default reply: A system-assigned reply to an inquiry or notify message, which is used when the message queue at which the message arrives is in default delivery mode.
default routing entry: In SNADS, the routing table entry specifying the route to be used when the table contains no explicit routing entry.
default user name: A system-provided name for a user identification for a computer system that does not want to require separate user identifications.
default value: A predetermined value, attribute, or option that is assumed when no other value is specified. A default value can be defined for column data in DB2 tables by specifying the DEFAULT keyword in an SQL statement that changes data (such as INSERT, UPDATE, and MERGE).
Defense Advanced Research Projects Agency (DARPA): The United States Department of Defense agency responsible for creating ARPANET, a large TCP/IP network.
Defense Data Network (DDN): The MILNET, ARPANET, and TCP/IP networks and protocols.
deferred maintenance: The process of waiting until the system can be powered down to repair or replace a failed disk-related hardware component.
deferred work element (DWE): The catalyst used to call event-driven services controlled within CICS®. A DWE causes a unit of work to be scheduled later, normally at the end of the task or just before or after syncpoint.
defined address: A named set of a) Internet Protocol (IP) addresses, or b) interface names and point-to-point profiles. This set is classified as trusted, untrusted, or border.
definite response (DR): In SNA, a value in the response-requested field of the request header that directs the receiver of the request to return a response unconditionally, whether positive or negative, to that request. See also exception response, no response.
definition specification: In RPG, a specification used for data definitions. This specification includes defining the following: data structures, data-structure subfields, named constants, arrays, and stand-alone fields.
defragmentation: The process of running a software utility to rewrite fragmented data to contiguous sectors of a computer storage medium to improve access and retrieval time. See also fragmentation.
delay characteristic: The average amount of time required for an operation (such as call setup, call clearing, data transfer, and so forth) to be performed on a packet-switching network.
delayed maintenance: A method of logging changes to an access path for database files and applying the changes the next time the file is opened instead of rebuilding the access path completely or maintaining it immediately. See also immediate maintenance, rebuild maintenance.
delegate: A user who is authorized to work for another user.
delegation: The process of propagating a security identity from a caller to a called object. According to the J2EE specification, a servlet and an enterprise bean can propagate either the client identity when invoking enterprise beans, or can use another specified identity as indicated in the corresponding deployment descriptor.
delete authority: A data authority that allows the user to remove entries from an object; for example, delete messages from a message queue or delete records from a file. See also add authority.
delete trigger: A trigger that is activated by a delete operation on the table or view that is specified in the trigger definition. See also insert trigger, trigger, instead of trigger, update trigger.
delimited identifier: A sequence of one or more characters enclosed by quotation marks (").
delimited scope statement: In COBOL, any statement that includes its explicit scope terminator.
delimiter: A flag that is formed by a character or a sequence of characters to group or separate items of data by marking the beginning and end of a unit of data. The delimiter is not a part of the flagged unit of data.
delimiter token: A string constant, a delimited identifier, an operator symbol, or any of the special characters shown in syntax diagrams.
delta channel (D-channel): In ISDN, a common channel used for signaling and management of the network. In a basic rate interface, the D-channel operates at 16 kilobits per second. In a primary rate interface, the D-channel operates at 64 kilobits per second. See also bearer channel.
demodulate: To return the frequency of a signal to its original level.
denial-of-service attack: In computer security, an assault on a network that brings down one or more hosts on a network such that the host is unable to perform its functions properly. Network service is interrupted for some period.
dependent file: The file in a constraint relationship that contains the foreign key. See also parent file.
dependent logical unit (DLU): A logical unit that requires assistance from a system services control point (SSCP) to instantiate an LU-to-LU session. See also independent logical unit.
dependent logical unit requester (DLUR): An advanced program-to-program communications (APPC) application that allows dependent secondary logical units (LU 0, 1, 2, and 3) an entry point into the Advanced Peer-to-Peer Networking (APPN) network. DLUR support gives the appearance of having an adjacent connection to VTAM®, but allows traversing the APPN network through intermediate nodes.
dependent row: A row that contains a foreign key that matches the value of a parent key in the parent row. The foreign key value represents a reference from the dependent row to the parent row. See also parent row.
dependent table: A table that is a dependent of an object. For example, a table with a foreign key is a dependent of the table containing the corresponding primary key. See also descendent table, parent table.
deploy: To place files or install software into an operational environment. For example, in a policy-enabled system, policies are deployed to the autonomic managers that are registered to receive those policies, putting those policies into effect in that operational environment.
deployment: The act of packaging enterprise beans into a JAR file for distribution to a container on an enterprise bean server.; The process of making WebSphere® Commerce application code available for use. This process includes packaging customized commands, data beans, and enterprise beans into JAR files. The JAR files must then be installed and configured within a container.
deployment code: Additional code that enables bean implementation code written by an application developer to work in a particular EJB runtime environment. Deployment code can be generated by tools that the application server vendor supplies.
dequeue: To remove items from a queue. See also enqueue.
dereference: In VisualAge RPG, to remove information specific to the System i platform from a control.
deregister: In the hierarchical file system, to remove an underlying file system and the specific functions it supports from the application programming interface layer and to make it unavailable to user applications.
derived form: A query management form that was built by converting a Query definition object.
derived name: In REXX, the stem of the symbol, in uppercase, followed by the tail in which all simple symbols have been replaced by their value. It is also the default value of a compound symbol.
derived query: A query management query that was built by converting a Query definition object.
DES: See Data Encryption Standard.
descendent row: A row that is a dependent of another row or is a descendent of a dependent of another row.
descendent table: A table that has a dependent relationship on a parent table or on another descendent table. See also dependent table.
descending key: The values by which data is arranged from the highest value to the lowest value of the key field, in accordance with the rules for comparing data items. See also ascending key.
descending key sequence: The arrangement of data in order from the highest value of the key field to the lowest value of the key field. See also ascending key sequence.
descending sequence: The arrangement of data in order from the highest value to the lowest value, according to the rules for comparing data. See also ascending sequence.
deselect: To cancel a previously selected object.
deselection: The process of removing selection from a previously selected object.
designated approving authority (DAA): The official who has the authority to accept the security safeguards for an information system. The DAA may be responsible for issuing an accreditation statement that records the decision.
design window: In VisualAge RPG, the window in the GUI design tool suite on which parts are placed to create a user interface.
destination address: The location to which information is to be sent. See also source address.
destination address field (DAF): In SNA, a field in a format identification 0 or format identification 1 transmission header that contains the network address of the destination. In a format identification 2 header, the field is called destination address field prime (DAF'). See also origin address field.
destination control table (DCT): A table describing each of the transient data destinations used in CICS. This table contains an entry for each extrapartition, intrapartition, and indirect destination.
destination node: In the OSI Communications Subsystem licensed program, a node that is the final recipient of data sent by the local node and the origin of data sent to the local node. A destination node may or may not be an adjacent node.
destination NSAP address: In OSI, an NSAP address that identifies a destination node.
destination service access point (DSAP): In OSI, a service access point used to receive data.; In SNA and TCP/IP, a logical address that allows a system to route data from a remote device to the appropriate communications support. See also source service access point.
destination system: In SNADS, a system that can receive messages, documents or objects.
destructive data change: An event in which data is modified by a change operation in an application or by a trigger, and then the data is modified again by other trigger actions within the same trigger.
detach: In a multithreaded environment, to mark a thread so that the system reclaims the thread resources when the thread ends. If the thread is already ended, the resources are freed immediately.; In cross-site mirroring, to disassociate a mirror copy from the production copy to use the mirror copy for a separate operation, such as to save data, to run reports, or to perform data mining. Detaching a mirror copy suspends geographic mirroring.
detached copy: The mirror copy of an independent disk pool that is disassociated from the production copy in a cross-site mirroring (XSM) environment.
detail calculation: In RPG, specified calculation operations that are performed for every record read.
detail line: In RPG, a detail record in an output file.
detail record: In RPG, an output record produced during the detail output operation of the RPG program cycle. See also total record.; A record that contains the daily activities or transactions of a business. For example, the items on a customer order are typically stored in detail records. See also header record.
detail report: In Query, a report that contains all the information produced by a query. See also summary report.
details view: A standard contents view in which a small icon is combined with text to provide descriptive information about an object. The text is arranged in rows and columns so one row is for each object and one column is for each type of descriptive information displayed.
detail time: That part of the RPG program cycle in which calculation and output operations are performed for each record read. See also total time.
detected access transmission error in (DTSE in): In Performance Tools, the number of times the network termination 1 (NT1) notifies the terminal equipment (TE) of an error in data crossing the U interface of the integrated services digital network (ISDN) from the line transmission termination (LT) to the NT1. The NT1 reports the errors to the TE through the maintenance channel S1.
detected access transmission error out (DTSE out): In Performance Tools, the number of times the network termination 1 (NT1) notifies the terminal equipment (TE) of an error in data crossing the U interface of the integrated services digital network (ISDN) from the NT1 to the line transmission termination (LT). The NT1 reports the errors to the TE through the maintenance channel S1.
determinant: A value resulting from a mathematical operation on an array.
DEVD: See device description.
development folder: In System Manager, a folder containing documents for a load that is being developed.
development library: In System Manager, the library containing all or part of a product that is being developed.
device: A piece of equipment. Devices can be workstations, printers, disk drives, tape units, or remote systems.
device address: A unique identifier for each device so it is recognized by the system.
device attributes feedback area: In the C language, an area that allows a user to obtain information about a specific device.
device class: The generic name for a group of device types. For example, all display stations belong to the same device class. See also device type.
device cluster resource group: A cluster resource group that contains a list of switchable devices, such as independent disk pools which reside on a switchable entity. See also switchable entity.
device configuration: The physical placement of display stations, printers, and so forth; and the configuration descriptions that describe the physical configuration to the system and describe how the configuration will be used by the system.
device dependence: The reliance on the characteristics of particular types of devices used in writing and running programs or in performing functions. See also device independence.
device-dependent: Pertaining to a function that can be accomplished, or a program that can be run, only if particular types of devices are available. See also device-independent.
device description (DEVD): An object that contains information describing a particular device or logical unit (LU) that is attached to the system. A device description is a description of the logical connection between two LUs (local and remote locations).
device domain: A collection of cluster nodes that share device resources, such as independent disk pools. For independent disk pools, the resources are: virtual addresses, disk pool numbers and disk unit numbers. An independent disk pool can only be accessed by the nodes in one device domain.
device driver (DD): A program that provides an interface between a specific device and the application program that uses the device.
device emulation: The programming that allows one device to appear to the user or to a system as another device.
device file: One of several types of the system object type *FILE. A device file contains a description of how data is to be presented to a program from a device or how data is to be presented to the device from the program. Devices can be display stations, printers, units, tape units, or remote systems.
device independence: The capability to write and run programs or perform functions without regard for the physical characteristics of devices. See also device dependence.
device-independent: Pertaining to a function that can be accomplished, or a program that can be executed, without regard for the characteristics of particular types of devices. See also device-dependent.
device name: The symbolic name of an individual device.
device object: An object that provides a means of communication between a computer and another piece of equipment, such as a printer or disk drive.
device parity protection: A function that protects data stored on a disk-unit subsystem from being lost because of the failure of a single disk unit in the subsystem. When a disk-unit subsystem has device parity protection and one of the disk units in the subsystem fails, the subsystem continues to run. The disk-unit subsystem reconstructs the data after the disk unit is repaired or replaced. See also checksum protection, mirrored protection, Redundant Array of Independent Disks.
device selection character: In BSC, the control character that is sent to a receiving system or to a device connected to a receiving system to select that device to receive the output.
device table: A list of finance devices supported by a server to be used by a finance job.
device token: In the GDDM function, an 8-byte code, required to set the devices to a predefined set of hardware characteristics.
device type: The generic name for a group of devices. See also device class.
DFC layer: See data flow control layer.
DFHAID: A COBOL copybook containing the symbolic names for all the AID keys in CICS.
DFU: See data file utility.
DHCF: See distributed host command facility.
DHCP: See Dynamic Host Configuration Protocol.
DIA: See Document Interchange Architecture.
diacritic: A mark indicating a change in the phonetic value of a character or a combination of characters.
DIA document distribution service: A service that allows users to send, receive, file, print, change details of, and query electronic mail.
diagnostic: Pertaining to the detection and isolation of an error.
diagnostic message: A message that contains information about errors or possible errors. This message is generally followed by an escape message.
dialed number identification service (DNIS): In telephony, a number supplied by the public telephone network to identify a logical called party. For example, two 800 numbers might both be translated to a single real telephone number. The DNIS is sent when the real telephone number is called to allow end users to distinguish which service is being called when a call arrives to the real number.
dialog: A series of related inquiries and responses between a user and an application, similar to a conversation between two people.
dialog box: A secondary window that solicits user input for a specific task or subtask. Common examples are the Print and Save As dialog boxes. Dialog boxes are modal; that is, they must be closed before the user can continue working in the window that launched the dialog box.
dialog management: In OSI, a session-layer service that controls which peer application entity has permission to send.
dialog variable: In the user interface manager (UIM), an element in a panel group that is used to pass data values between two programs or between a program and a user. The values for all dialog variables in a panel group are stored in a variable pool.
Dial-Up Networking: Microsoft software personal computers running Windows that allows a modem to dial into a server.
DIB: See directory information base.
DIF: See data interchange format.
Differentiated Services: A quality-of-service standard between two networks that allows hosts to manage data by traffic flow.
Differentiated Services domain: A contiguous portion of the Internet over which a consistent set of Differentiated Services policies are administered. A Differentiated Services domain can represent different trust regions, different network technologies (such as cells or frames), different hosts, or even different routers.
Differentiated Services field: A six-bit field in the Internet Protocol (IP) header of a data packet that encodes the Differentiated Services code point. The field replaces the IPv4 IP header field, which is called type of service (ToS).
Diffie-Hellman group: A public, key-exchange algorithm that is used for securely establishing a shared secret over an insecure channel. During Phase II negotiations, the Diffie-Hellman group prevents someone who intercepts your key from deducing future keys that are based on the one they have.
digit: Any of the numerals from 0 through 9.
digital: Pertaining to data in the form of digits. See also analog.
digital certificate: An electronic document used to identify an individual, a system, a server, a company, or some other entity, and to associate a public key with the entity. A digital certificate is issued by a certification authority and is digitally signed by that authority.
Digital Certificate Manager (DCM): An IBM i component that allows IBM i to be a local Certificate Authority (CA) to create digital certificates that are used to ensure secure communications.; An IBM i option that registers certificates that are created on the system when it is acting as a certificate authority (CA). DCM can also be used to register certificates that other certificate authorities issue. DCM allows you to choose to associate a user's certificate with its user profile. DCM is also used to associate digital certificates with various applications so that these applications can use the Secure Sockets Layer (SSL) for secure communications.
digital data service adapter (DDSA): In data communications, a device used when sending and receiving data using a nonswitched digital data service.
digital envelope: In the context of SET programs, a package of encrypted data and the encryption key.
digital signature: Information that is encrypted with a private key and is appended to a message or object to assure the recipient of the authenticity and integrity of the message or object. The digital signature proves that the message or object was signed by the entity that owns, or has access to, the private key or shared-secret symmetric key.
digital versatile disc: See digital video disc.
digital video disc (DVD): An optical disc that has the same overall dimensions of a CD-ROM, but has significantly higher capacities than a CD-ROM. DVDs are also double sided, whereas CD-ROMs are single sided.
digit position: In COBOL, the amount of physical storage required to store a single digit. This amount can vary depending on the usage specified in the data description entry that defines the data item. If the data description entry specifies that the USAGE IS DISPLAY, then a digit position is synonymous with a character position.
dimension: In System Manager, the interfaces that define guidelines, standards, services, and other interfaces for integrating systems management applications.
DIMM: See dual inline memory module. See also single inline memory module.
direct access: A file access method allowing reading and writing of records in an arbitrary order.
direct access storage device (DASD): A device that allows storage to be directly accessed, such as a disk drive. See also random access memory.
directive: A keyword in the startup file that identifies one aspect of the configuration. Examples of directives are directory, primary, secondary, cache, forwarders, sortlist, $include, options, xfrnets, and bogusns.; A statement that is used in the configuration file for a Web server to define a particular setting for the server.
direct manipulation: The use of a pointing device to work with objects, rather than through menus. For example, changing the size of a window by dragging one of its edges is direct manipulation.
direct monitor handler: An exception handler that allows the application programmer to directly declare an exception monitor around limited high-level language source statements. For ILE C, this capability is enabled through the #pragma statement.
directory: A collection of open systems that cooperate to hold a logical database of information about a set of objects in the real world.; In OSI, a repository of information about objects. As defined in the X.500 directory standards, a directory is both a repository of information and the set of services provided to enable its users to access the information in the repository.; A type of file that contains the names and controlling information for objects or other directories.; In a hierarchical file system, a grouping of related files and directories. A directory can contain zero or more entries, which refer to other directories and files.
directory access protocol (DAP): In OSI, the X.500 protocol that a directory user agent uses to obtain directory information from a remote directory system agent.
directory entry: A entry in the system distribution directory. A directory entry contains information about the user, such as user ID and address, system name, profile name, mailing address, and telephone number.
directory information base (DIB): In OSI, an X.500 term indicating a collection of all directory information in a directory system made up of one or more cooperating directory system agents.
directory pointer: In the hierarchical file system, the representation of the position of the next directory entry to be read.
directory server: A server that can add, delete, change, or search directory information on behalf of a client.
Directory Server: See IBM Tivoli® Directory Server for IBM i.
directory service: In OSI, the service by which an open system can access directory information. Directory service can be provided locally within an open system, or it can be obtained from another open system using the directory service protocols defined by ISO/CCITT. In OSI Communications Subsystem, directory service is used to obtain the presentation address and other attributes of application entities.
directory shadowing: The capability of a system to duplicate Enterprise Address Book (EAB) data from one installation of the EAB to another, such that whenever an addition, change, or deletion is made to the EAB on a given system, it is available to all EAB installations within the network.
directory system agent (DSA): In Open Source Initiative (OSI), an application process residing in an open system that provides directory service to other open systems.
directory user agent (DUA): In OSI, an application process residing in an open system that serves as the agent that obtains directory services for that open system. The agent can obtain the services either locally or from a remote directory system agent.
DISC: See disconnect.
discipline: In System Manager, a grouping of systems management tasks that support an enterprise's information system environment. Examples of disciplines are change management and problem management.
disconnect (DISC): In communications, the transmission control character that is part of the sequence for disconnecting a switched line.
disconnect character: In data communications, the part of the BSC transmission control sequence for ending the connection on a switched line.
disconnected mode (DM): In communications, a response from a secondary station indicating that it is logically disconnected from the link.
disconnect timeout: An indication that a switched BSC connection was disconnected because there was no activity on the connection for a specified length of time.
discovery: The automatic detection of a network topology change, for example, new and deleted nodes or links.
disk: A storage device that includes one or more flat, circular plates with magnetic or optical surfaces on which information is stored.
disk drive: The mechanism used to read and write information on a disk.
disk enclosure: The part of a disk unit that contains the read and write heads, the magnetic disks, and the actuators.; A sealed container that holds the read/write head and disk assembly within a disk unit.
: A thin, flexible magnetic plate that is permanently sealed in a protective cover. It can be used to store information copies from the disk or another .
file: A device file created by the user for a unit.
unit: A physical enclosure containing one or more drives.
disk operating system (DOS): An operating system for computer systems that use disks and s for auxiliary storage of programs and data.
disk pool: An auxiliary storage pool that contains only disk units.
disk pool group: Made up of a primary disk pool and zero or more secondary disk pools, each of which are independent in regard to data storage, but combine to act as one entity.
disk unit: A sealed container that holds the read and write heads, the magnetic disks, and the actuators. See also random access memory.
disk unit enclosure: A physical enclosure containing one or more disk units.
displacement: The distance from the beginning of a record, block, or segment to the beginning of a particular field.
display attribute: In computer graphics, a property that is assigned to a display element, to a display segment, or to the complete display image; for example, a bright intensity or particular color.
display file: A device file to support a display station.
display image: In 3270 emulation, the x-character block (where x is the maximum number of characters that can fit on the display screen, or 1920 for printers) that contains data in the sequence in which it would appear on the display screen or the printer. When creating the display, the user can specify the display image with or without field definitions, such as position, length, and other attributes.
display layout sheet: In SDA, a form used to plan the location of data on the display.
display point: In the GDDM function, the smallest addressable area on the screen, sometimes called a picture element (pel), that defines the resolution of the characters or images.
display screen: See screen.
display session: A PC program that allows a personal computer to emulate a display station.
display station: A device, usually equipped with a keyboard and a display device, capable of sending and receiving information over a communications line.
display station pass-through: A communications function that allows a user to sign on to one system (such as a System i, a System/38, or a System 36 system) from another system (such as a System i, a System/38, or a System 36 system) and use that system's programs and data.
distinguished name: In Open System Interface (OSI), a multipart hierarchical name that can be used to identify OSI objects globally. The distinguished name of an object is formed from the sequence of its relative distinguished names (RDNs) and the name of its superior object.; A set of name-value pairs (such as CN=person's name and C=country or region) that uniquely identifies an entity in a digital certificate.
distributed application: In message queuing, a set of application programs that can each be connected to a different queue manager, but that collectively comprise a single application.
distributed computing: A method of computing in which large problems are divided into small tasks that are distributed across a network for simultaneous processing. Individual results are then brought together to form the total solution.
distributed data: Data that is stored on more than one system and is available to remote users and application programs.
distributed database: A database that appears to users as a logical whole, locally accessible database, but consists of databases in multiple locations that are connected by a data communications network. See also distributed file management.
distributed data interface (DDI): An optical fiber-based LAN using the ANSI X3T9.5 standard for a token-passing ring MAC protocol and its physical attachments. Stations, concentrators, and bridges in a DDI network are physically connected to one or both of a pair of counter-rotating rings operating at 100Mbps. The term DDI is used to represent all LAN types based on the fiber distributed data interface (FDDI) specifications, regardless of the media used (optical fiber, copper, or shielded twisted pair).
distributed data management (DDM): A function of the operating system that allows an application program or user on one system to use database files stored on remote systems. The systems must be connected by a communications network, and the remote systems must also be using DDM.
Distributed Data Management Architecture (DDM Architecture): A connection protocol that enables communication between a system that uses distributed file management and a system that uses distributed relational database architecture.
distributed file management: A function of the operating system that allows an application program or user on one system to use database files stored on remote systems. The systems must be connected by a communications network, and the remote systems must also be using distributed file management. See also distributed database.
distributed host command facility (DHCF): A function of the operating system that supports the data link between a System/370 terminal using a System i application in an HCF (Host Command Facility) environment.
distributed processing: Processing in which resources or functions are dispersed among two or more interconnected processors, typically over a network.
distributed program link (DPL): A function of CICS intersystem communication that enables an application program to ship LINK requests to another application program on a different instance of CICS.
Distributed Protocol Interface (DPI): An extension to the Simple Network Management Protocol (SNMP) agent that permits users to dynamically add, delete, or replace management variables in the local Management Information Base (MIB) without requiring recompilation of the SNMP agent.
distributed queue management: In message queuing, the setup and control of message channels to queue managers on other systems.
distributed relational database: A database whose tables are stored on different but interconnected computing systems.
Distributed Relational Database Architecture™ (DRDA): The architecture that defines formats and protocols for providing transparent access to remote data. DRDA defines two types of functions: the application requester function and the application server function.
distributed systems node executive (DSNX): A function of the operating system that receives and analyzes requests from the NetView® Distribution Manager licensed program on a host system. If the request is directed to the system that receives it, the request is processed on that system or on a personal computer directly attached to that system. If the request is intended for a different system, it is routed toward its destination.
distributed transaction processing (DTP): A process that enables a CICS transaction to communicate synchronously with a transaction running in another instance of CICS.
distributed unit of work (DUOW): A unit of work that allows SQL statements to be submitted to multiple relational database management systems, but no more than one system per SQL statement.
distribution catalog: A list of objects, with references to their locations and associated object characteristics.
distribution document: An internal document that contains the document content and the document details for a distribution, such as a note or document.
distribution list: A list of system distribution directory entries, which allows users to send messages, notes, and documents to a group of users in one step.
distribution media: The medium on which the operating system software, a licensed program, or an application program is distributed to the user. The distribution medium can be any of several different media supported by the hardware, such as streaming cartridge tape, 9-track tape, or 3.5-inch .; The media that a central site creates and distributes to target systems. See also installation media.
distribution queue: In SNADS, a list of documents or mail waiting to be sent to users or libraries on remote systems.
distribution recipient index: See distribution recipient queue.
distribution recipient queue: An internal object that contains entries for incoming object distributions; incoming document distributions, such as files, notes, or messages; outgoing document distributions; and error distributions.
distribution repository: In Managed System Services, a staging area for objects that are to be sent or have been received. Objects are loaded into the repository to be sent to managed systems at a later time.
distribution requisite fix: A temporary solution to or a bypass of a problem that is necessary to provide a complete solution to correct a problem. The system allows you to apply the distribution requisite fix either before the PTF that needs it, with the PTF that needs it, or after the PTF that needs it. See also corequisite fix, prerequisite fix.
distribution service level: In SNADS, the combination of priority, capacity, and protection requirements that must be satisfied to receive or send a distribution. SNADS has service levels of fast, status, data high, and data low. Items with a service level of fast, status, or data high are put on the priority queue. Items with a service level of data low are put on the normal queue.
distribution services: The support provided by the operating system to receive, forward, and send electronic mail in an SNA network.
distribution tracking object: An internal object that is used to control electronic mail.
division header: In COBOL, the reserved words and punctuation that indicate the beginning of one of the four divisions of a COBOL program.
DLC: See data link control protocol.
DLCI: See data link connection identifier.
DLC layer: See data link control layer. See also data flow control layer.
DLE: See data link escape character. In binary synchronous communication (BSC), a transmission control character used to indicate that the next character is a control character, not a data character.
DLE character: See data link escape character. In binary synchronous communication (BSC), a transmission control character used to indicate that the next character is a control character, not a data character.
DLL: See dynamic link library.
DLO: See document library object. See also document.
DLU: See dependent logical unit. See also independent logical unit.
DLUR: See dependent logical unit requester.
DM: See disconnected mode.
DNIC: See data network identification code. See also data country code.
DNIS: See dialed number identification service.
DNS: See Domain Name System. See also domain name.
DNS domain database file: A configuration file that contains information about the domain, such as resource records, that a server administers.
DNS server cache: Periodically updated information on a name server that contains data about the domain that the name server administers.
document: Any collection of data stored in a document object. A document can contain any type of data. For example, the System i Access shared folders function can store any data that could otherwise be stored in a PC file; a server application can store any data into a document by using CL commands, such as FILDOC and RPLDOC. The system-recognized identifier for the document object type is *DOC. See also document library object.
document authority: The definition of what actions a user can perform on a document.
document class: A user-defined character string, 1 through 16 characters long, that characterizes a document. It can be used to search for a filed document. For example, a document that is a memo could have a document class of MEMO; a document that is a report, REPORT.
Document Content Architecture (DCA): An architecture that guarantees information integrity for a document being interchanged in an office system network. DCA provides the rule for specifying form and meaning of a document. It defines revisable form text (changeable) and final form text (unchangeable).
document description: The 1- through 44-character description of a document, assigned by the user when creating or filing the document.
document detail: Data that describes a characteristic of a document. For example, a detail can be document type, subject, author, or date created.
document format: The selected arrangement of text for a specific document.
Document Interchange Architecture (DIA): The rules and structure for the exchange of information between office applications. Document Interchange Architecture includes document library services and document distribution services.
document interchange session: The environment that allows office system users and System i Access users to request document library and distribution services from the host system.
document library: The entire collection of documents and folders on a system.
document library object (DLO): Any system object that resides in the document library, such as RFT and FFT documents, folders, and PC files. See also document.
document library services: The services defined by the Document Interchange Architecture (DIA) to work with objects filed in the DIA document library. On the system, it is the support that lets users work with the contents of the document library.
document name: The 1- through 12-character name for documents in folders, assigned by the user when creating the document. See also document object name.
document number: The number assigned to a printed document when a user files that document. The first two digits of the document number are the year, and the last five are in sequence, with the most recent documents having the highest number. For example, the fifth printed document filed in 1989 would have the number 89-00005.
document object name: The 10-character name of a document assigned by the system when a user files the document. See also document name.
document type definition: The definition of a non-Document Interchange Architecture (DIA) document user type that identifies the document type number, name, and text associated with the document.
document type set: A value that allows a logical grouping of document type definitions. Document type sets include the name and the description. A set can contain one or more document types or it can be empty.
document unit object: An internal object that contains the document content and the document details.
DO group: In RPG, a group of calculations done one or more times based on the results of comparing factor 1 and factor 2 of certain calculation operations (for example, DOUxx). A DO operation and an END operation are the delimiters for a do group.; A set of commands in a control language program defined by a DO command and an ENDDO command that is conditionally processed as a group.
DOI: See Domain of Interpretation.
DO loop: A range of statements run repetitively by a DO statement.
domain: In TCP/IP, a named set of hosts. Each domain has authority for the machines within that domain, but not for machines in other domains.; A characteristic of an object that controls which programs can access the object. See also system domain object, user domain object.; A set of systems that allocate shared network resources within a single logical system.; In a database, the set of valid values for an attribute.; A logical grouping of resources in a network for the purpose of common management and administration.; In communications, the network resources under control of a particular system services control point (SSCP).
domain-defined attribute: In OSI X.400, an attribute of the X.400 originator/recipient name that permits a System i product to keep existing addressing conventions. The System i product uses the domain-defined attributes to carry the user ID and address (the two-part network name used in SNADS).
domain name: In Internet communications, a name of a host system. A domain name consists of a sequence of subnames that are separated by a delimiter character, for example, www.ibm.com. See also Domain Name System.
domain name server: In Internet communications, a server program that supplies name-to-address conversion by mapping domain names to IP addresses.
domain name space: All of the names in the Domain Name System (DNS).
Domain Name System (DNS): The distributed database system used to map domain names to IP addresses. See also domain name.
Domain of Interpretation (DOI): A group of related protocols that uses the Internet Security Association and Key Management Protocol (ISAKMP) to negotiate Security Associations (SAs). A DOI defines payload formats, exchange types, and conventions for naming security-relevant information such as security policies and cryptographic algorithms and modes.
Domino connector: A function of the HTTP Server for IBM i licensed program that enables Lotus Notes® users to access the Internet and to use all of the HTTP Server functions. Specifically, a Domino connector enables Lotus Notes users to combine Notes with e-business applications.
Domino directory: A database that provides a domain-wide directory of Domino servers, users, certifiers, foreign domains, and groups. It also contains documents that manage server-to-server communication and server programs.
Domino for IBM i: See Lotus Domino for IBM i.
dormant state: In DB2 for IBM i, the state of a connection when the connection is suspended. While in the dormant state, no SQL statements use the connection except for commits and rollbacks. See also current state.
DOS: See disk operating system.
DOS session: A session that supports the independent running of a DOS program. The DOS program appears to run independently of any other programs in the system.
dot matrix: In word processing, a pattern of dots used to form characters.; In computer graphics, a two-dimensional pattern of dots that are used for designing an image on the display.
dotted decimal notation: The syntactical representation for a 32-bit integer that consists of four 8-bit numbers written in base 10 and separated by dots. IP addresses are represented in dotted decimal notation. See also octet.
double-byte character: An entity that requires two character bytes.
double-byte character large object (DBCLOB): A data type that contains a sequence of double-byte characters that can range in size from 0 bytes to 2 gigabytes less one byte. This data type can be used to store large double-byte text objects.
double-byte character set (DBCS): A set of characters in which each character is represented by two bytes. These character sets are commonly used by national languages, such as Japanese and Chinese, that have more symbols than can be represented by a single byte. See also single-byte character set, multibyte character set.
double-byte coded font (double-byte font): A font in which the characters are defined by 2 bytes. The first byte defines the coded font section; the second byte defines the code point in the code page specified for that section.
double-byte font: See double-byte coded font.
double-click: To press and release a mouse button twice in rapid succession in order to perform an operation.
double precision: The specification that causes a floating-point value to be stored (internally) in the long format (two computer words). See also single precision.
downline: Pertaining to devices that are below a controller, and controllers that are below a communications line in a communications configuration. See also upline.
download: To transfer data from a computer to a connected device, such as a workstation or personal computer.
downstream: Pertaining to the direction of data flow, which is toward the destination of a transmission. See also upstream.
DPI: See Distributed Protocol Interface.
DPL: See distributed program link.
DR: See definite response. See also exception response, no response.
drag: To use a pointing device to move an object. For example, a user can drag a window border to make it larger by holding a button pointing device while moving the pointing device.
drawing character: In System i Access, a keyboard character that is placed in the cursor position after the cursor is moved with the cursor movement key.
DRDA: See Distributed Relational Database Architecture.
DRDA1: The first stage of Distributed Relational Database Architecture (DRDA). In this stage, an application or user on one system can, within a single unit of work, read update data on a single DBMS.
DRDA2: The second stage of Distributed Relational Database Architecture (DRDA).
driver: A circuit that increases the signal current for sending data over long cables or to many other circuits.; A circuit that sends small electronic signals to a device.
dropping: In QoS, the simplest form of traffic conditioning where noncompliant packets are discarded.
DSA: See directory system agent.
DSAP: See destination service access point. See also source service access point.
DSD: See Dedicated Server for Domino.
DSNX: See distributed systems node executive.
DST: See dedicated service tools.
DST-restricted state: The status of the system before an initial program load (IPL) of the operating system is performed. Only dedicated service tools functions are allowed when the system is in the DST-restricted state.
DSU: See Data Description Specifications Design Utility.; See data service unit.
DTE: See data terminal equipment.
DTE address: An address that identifies a specific line attached to a given node on an X.25 network. DTE addresses are assigned by the network supplier.
DTE attribute: In OSI, an attribute specified by the local node to regulate connection requests with an adjacent node on an X.25 subnetwork.
DTP: See distributed transaction processing.
DTSE in: See detected access transmission error in.
DTS entity: In the DCE Distributed Time Service, the server or clerk software on a system.
DTSE out: See detected access transmission error out.
DUA: See directory user agent.
dual-homed host: See multihomed host.
dual inline memory module (DIMM): A small circuit board with memory-integrated circuits containing signal and power pins on both sides of the board. See also single inline memory module.
dummy device: In the GDDM function, an imaginary output device for which the program does all the normal processing but for which no actual output is received.
dump: Data that is copied in a readable format from main or auxiliary storage to an external medium such as tape, , or printer.; To record or copy, at a particular instant, data from one storage device onto another storage device to protect the data and debug the program.
dump media: The or the tape to which the user writes the storage dumps.
DUOW: See distributed unit of work.
duplex: Pertaining to communication in which data can be sent and received at the same time. See also half-duplex.; Pertaining to printing on both sides of a sheet of paper.
duplicate key value: The occurrence of the same value in a key field or in a composite key in more than one record in a file.
duration: In Backup, Recovery, and Media Services, the length of time that the designated media is to reside at a location before moving to the next location or returning to the home location. A duration is specified in the move policy.; In SQL, a number that represents an interval of time.
DVD: See digital video disc.
DWE: See deferred work element.
dynamic: Pertaining to events that occur at run time or during processing.
dynamic access: In COBOL, an access method in which specific logical records can be obtained from or placed into a mass storage file in a nonsequential manner and obtained from a file in a sequential manner during the scope of the same OPEN statement.
dynamic bind: A process by which SQL statements or XQuery expressions are bound when they are executed. See also static bind, automatic bind.
dynamic connection: A virtual private network (VPN) connection that automatically refreshes the keys that keep data secure. A dynamic connection also contains proposals that allow the key server to negotiate which parameters to use with the remote key server. See also manual connection.
dynamic data exchange (DDE): The exchange of data between programs or between a program and a data-file object. Any change the user makes to information in one program or session is applied to the identical data created by the other program. For example, with the DDE feature enabled, the user can select the copy of a spreadsheet that is embedded in a report. If the user makes changes to the copy of the spreadsheet in the report, the changes are made to the original spreadsheet file.
Dynamic Host Configuration Protocol (DHCP): A communications protocol that is used to centrally manage configuration information. For example, DHCP automatically assigns IP addresses to computers in a network.
dynamic IP: A method of Internet Protocol (IP) address management in which Dynamic Host Configuration Protocol (DHCP) assigns IP addresses to hosts and updates the host IP records in the Domain Name System (DNS). This method keeps DNS records current as IP address assignments change.
dynamic IP address: A temporary IP address for a transient device or logical unit on a network: for example, a personal computer. See also IP address.
dynamic IP connection: A virtual private network (VPN) connection between a local endpoint and a host with a dynamically assigned Internet Protocol (IP) address.
dynamic link library (DLL): A file containing executable code and data bound to a program at load time or run time, rather than during linking. The code and data in a DLL can be shared by several applications simultaneously.
dynamic naming: In System Manager, the attribute of an application option that specifies whether the option can be stored in libraries and folders named at the time the installation is performed. This attribute allows an application program to be stored even if a library or folder with the same name as one of the application program's primary libraries or folders is already on the customer's system, but is used by an application program with a different registration identifier.
dynamic print management: The use of the PrintManager™ program to make changes to a print operation without interrupting system functions.
dynamic processing: A method of reading from or writing to a file in a nonsequential order (see random processing) and reading from a file in a sequential order (see sequential processing) with the same OPEN statement.
dynamic program call: A transfer of control from one program or procedure to another program (*PGM) at run time. A dynamic program call is the only way that an original program model (OPM) program can connect to another OPM program. See also static program call.
dynamic retrieval: A storage management operation where selected data is restored back to disk. The retrieval can be either from tape to disk or from disk to disk.
dynamic route: A path that can be automatically located from a peer (locally attached) gateway.
dynamic select/omit: Selection and omission of logical file records performed during processing, instead of when the access path (if any) is maintained. Dynamic select/omit may also be used when no keyed access path exists.
dynamic SQL: An SQL statement that is prepared and executed at run time. In dynamic SQL, the SQL statement is contained as a character string in a host variable and is not precompiled. See also static SQL.
dynamic storage: An area of storage that is explicitly allocated by a program or procedure while it is running. See also static storage, automatic storage.
dynamic string: See string.
dynamic Web content: Programming elements such as JavaServer Pages (JSP) files, servlets, and scripts that require client or server-side processing for accurate runtime rendering in a Web browser.