Index | A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| data dictionary: | a textual description of each class, its associations, attributes, and operations |
| data flow: | the connection between the output of one object or process and the input to another |
| data flow diagram: | a graphical representation of the functional model, showing dependencies between values and the computation of output values from input values without regard for when or if the functions are executed. |
| datagram: | a packetlike communication mechanism that is addressed to a process rather than a host computer |
| data store: | a passive object that stores data for later access. |
| data transfer rate: | the speed (in bits per second) at which data can be transferred between two computers once transmission has begun |
| decimal: | base 10 number system; a number system with ten digits:
0 1 2 3 4 5 6 7 8 9 |
| decimal fraction: | a fraction whose denominator is a power of 10 |
| delegation: | an implementation mechanism in which an object, responding to an operation on itself, forwards the operation to another object; a mechanism in which methods may be attached directly to instances and where the method resolution is performed by searching a chain of instance pointers, rather than by searching a class heirarchy. |
| derived association: | an association that is defined in terms of other associations |
| derived attribute: | an attribute that is computed from other attributes |
| descendent class: | a class that is a direct or indirect subclass of a given class |
| despatcher: | a procedure (on the server) that uses the procedure identifier of a client request message to select one of the server procedures and pass the client's arguments to it |
| directory service: | a service that provides a mapping between file names and their UFIDs |
| discriminator: | an attribute of enumeration type that indicates which property of a class is being abstracted by a particular generalization |
| distributed mutual exclusion: | a mechanism for controlling resource access that involves allowing access to only one process at a time |
| distributed system: | a collection of autonomous computers linked by a computer network and equipped with distributed system software that enables the computers to coordinate their activities and to share hardware, software, and data |
| domain transition: | a switch between execution environments |
| duplex: | a term applied to data transmission where data can be both
sent and received
See also half-duplex and full-duplex; contrast with simplex |
| dynamic method binding: | choosing the correct method to call at runtime based on an object's actual type, and not the type of reference referring to it |
| dynamic method lookup: | See dynamic method binding |
| dynamic model: | a description of aspects of a system concerned with control, including time, sequencing of operations, and interaction of objects |