Data governance An organizational process for establishing
strategy, objectives, and policies for organizational data.
Data independence A highly desirable characteristic of data
stored in a database in which the data are independent of the data-
base structure or the physical organization of the data. Thus data
can be selected from a disk file by referring to the content of
records, and systems professionals responsible for database
design can reorganize the physical organization of data without
affecting the logic of programs.
Data mining Searching or “mining” for “nuggets” of informa-
tion from the vast quantities of data stored in an organization’s
data warehouse, employing a variety of technologies such as
decision trees and neural networks. See alsoData warehousing.
Data model A map or blueprint for organizational data. A data
model shows the data entities and relationships that are important
to an organization. See alsoEntity-relationship diagram.
Data standards A clear and useful way to uniquely identify
every instance of data and to give unambiguous business meaning
to all data. Types of standards include identifiers, naming, defini-
tion, integrity rules, and usage rights.
Data steward A business manager responsible for the quality
of data in a particular subject or process area, such as customer,
product, or billing.
Data transfer and integration application An application
that moves data from one database to another or otherwise brings
together data from various databases. These applications permit
one source of data to serve many localized systems within an
organization.
Data warehouse A very large database or collection of data-
bases, created to make data accessible to many people in an
organization. See alsoData warehousing.
Data warehousing The establishment and maintenance of a
large data storage facility containing data on all or at least many
aspects of the enterprise; less formally, a popular method for
making data accessible to many people in an organization. To
create a data warehouse, a firm pulls data from its operational
transaction processing systems and puts the data in a separate
“data warehouse” so that users may access and analyze the
data without endangering the operational systems. See alsoData
mining.
Data warehousing appliance An increasingly popular way of
creating a data warehouse, in which the organization purchases a
packaged solution consisting of hardware (i.e., server, storage)
and software (i.e., operating system, database management
system, other data warehousing software), where the software
has been specifically pre-installed and pre-optimized for data
warehousing.
Database A shared collection of logically related data that is
organized to meet the needs of an organization.
Database administrator (DBA) The person in the data
administration unit who is responsible for computerized databases.
A DBA is concerned with efficiency, integrity, and security of
database processing.
Glossary 673Database architecture A description of the way in which the
data are structured and stored in a database.
Database management system (DBMS) Support software
that is used to create, manage, and protect organizational data.
A DBMS is the software that manages a database; it works with
the operating system to store and modify data and to make data
accessible in a variety of meaningful and authorized ways.
DBA SeeDatabase administrator.
DBMS SeeDatabase management system.
DDD SeeDirect Distance Dialing.
DD/D SeeData dictionary/directory.
Decision support system (DSS) A computer-based system,
almost always interactive, designed to assist managers in making
decisions. A DSS incorporates both data and models and is usually
intended to assist in the solution of semistructured or unstructured
problems. An actual application that assists in the decision-making
process is properly called a specific DSS; examples of specific
DSSs include a police-beat allocation system, a capacity planning
and production scheduling system, and a capital investment
decision system.
Denial-of-service attacks A method of crippling a computer
by invading a large number of computers on the Internet and
instructing them to simultaneously send repeated messages to a
target computer, thus either overloading that computer’s input
buffer or jamming the communication lines into the target
computer so badly that legitimate users cannot obtain access.
Desktop PC The most common type of personal computer,
which is large enough that it can not be moved around easily. The
monitor and the keyboard, and sometimes the computer case
itself, sit on a table or “desktop.” If the computer case sits on the
floor under the table or desk, it is called a “tower” unit.
Desktop virtualization In this type of virtualization, the
desktop environment—everything the user sees and uses on a PC
desktop—is separated from the physical desktop machine and
accessed through a client/server computing model. This virtual-
ized desktop environment is stored on a server, rather than on the
local storage of the desktop device; when the user works from his
or her desktop device, all the programs, applications, and data are
kept on the server and all programs and applications are run on
the server. The server does almost all the work, so a thin client is
a very appropriate desktop device, which saves the organization
money.
DFD SeeData flow diagram.
Digital liability An organization’s liability related to the
mismanagement of electronic records.
Digital network The electronic linking of devices, where
messages are sent over the links by directly transmitting the zeros
and ones used by computers and other digital devices. Computer
telecommunications networks are digital networks, and the tele-
phone network is gradually being shifted from an analog to a
digital network.
Digital Subscriber Line A high-speed, or broadband, con-
nection to the Internet using already installed telephone lines.