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`NETWORK-1 N1-2009
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`

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`Copyright © 2004 by John Wiley & Sons, Inc. All rights reserved.
`
`Published by John Wiley & Sons, Inc., Hoboken, New Jersey.
`Published simultaneously in Canada.
`
`No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by
`any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted
`under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior Wiitten
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`may not be available in electronic format.
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`Librmy of Congress Cataloging-in-Publication Data is available.
`
`Kaplan, Steven M.
`
`Wiley Electrical and Electronics Engineering Dictionary
`
`ISBN 0-471-40224-9
`
`Printed in the United States of America.
`
`10 9 8 7 6 5 4 3 2 I
`
`

`
`data management
`
`167
`
`data redundancy
`
`data management The handling of data at all stages and
`levels, including input, coding, storage, processing, retrieval,
`and output. This includes the functions that the hardware,
`software, and users perform. For instance, a user can deter(cid:173)
`mine which data is to be acquired, an application program
`can manipulate and organize this information, while the op(cid:173)
`erating system enables the hardware to process and store the
`data properly.
`data management program A program, such as that used
`within a DBMS, that perfonns data management functions.
`data management system Same as DBMS. Its abbreviation
`isDMS.
`data manipulation Any of the various manners in which data
`is processed or organized, including sorting, editing, or
`merging.
`data manipulation language In a DBMS, a language utilized
`to locate, retrieve, store, update, and delete data from a data(cid:173)
`base. An example is a query language. Its abbreviation is
`DML.
`data mart A smaller version of a data warehouse. It may be
`utilized, for instance, to store information for one of many
`departments. Also spelled datamart.
`data medium Any physical material or medium which serves
`to store or otherwise contain data. For instance, optical
`discs, magnetic tapes and disks, microfilm, and paper. Also
`called data-storage medium, medium (3), or storage me(cid:173)
`dium.
`data migration I. The process of moving data from one stor(cid:173)
`age source or device, such as a database or tape, to another.
`2. The automatic transfer of information between storage
`media with different priorities. For example, the movement
`of data from a lower speed medium, such as an optical disk,
`to a hard disk when needed. This allows more data to be
`stored than if all was in the higher speed, and hence more
`expensive, medium. Also called hierarchical storage
`management.
`data mining The process of analyzing data to identify rela(cid:173)
`tionships and patterns which may be useful. Such mining
`may be done manually or automatically, through the use of
`specialized programs. Also called mining.
`data mirroring I. The duplication of stored data at a remote
`location, on another drive, another medium, or the like.
`Used, for instance, for backing-up, disaster recovery, or as a
`security measure. Also called mirroring (2). 2. The main(cid:173)
`taining of identical copies of data and files at multiple net(cid:173)
`work sites or servers. For example, an entity which receives
`many download requests from around the world may have
`many diversely located mirror sites to facilitate access. Also
`called mirroring (3).
`data model The stnrcture or design, including the organiza(cid:173)
`tion, data formats, and interrelations, of a database. Also, a
`graphical representation of such a model.
`data modem A modem that does not support fax protocols,
`thus does not have fax capabilities.
`data module A sealed unit which encloses one or more mag(cid:173)
`netic disks and their associated components, such as access
`arms.
`data name A name used to designate a data field, data ele(cid:173)
`ment, or data item.
`data network A system of computers, transmission channels,
`and related resources which are interconnected for the ex(cid:173)
`change data. It is a type of communications network.
`data organization The manner in which data is arranged in a
`database or storage medium. For instance, the sequential
`storage of data.
`Data Over Cable Service Interface Specification Same as
`DOCSIS.
`data packet Also called packet. I. A block of data transmit(cid:173)
`ted between one location and another within a communica-
`
`tions network. Also called information packet. 2. A block
`of data of a specific size or of a maximum size, transmitted
`in a packet-switching network. In addition to the payload, a
`packet contains information such as the source and destina(cid:173)
`tion addresses. When used in the context of TCP/IP net(cid:173)
`works, also called datagram.
`data parallel A computer architecture in which multiple
`processors simultaneously and independently execute the
`same instruction set on different sets of data. Also called
`single instruction stream-multiple data stream.
`data port A jack or socket used for data communications,
`especially one to which a modem can be connected to. Also
`spelled dataport.
`data processing Its abbreviation is DP. Also called auto(cid:173)
`matic data processing, electronic data processing, or in(cid:173)
`formation processing. I. The processing of information by
`a computer. 2. The processing of information within a spe(cid:173)
`cific application. For example, the manipulation of large
`amounts of numeric data in a program.
`data-processing center Same as datacenter.
`data-processing equipment Equipment used for data proc(cid:173)
`essing. Such equipment includes computers and any pe(cid:173)
`ripherals used in this process. Also called data-processing
`system (1 ), or electronic data-processing equipment.
`data-processing system
`Also called electronic data-
`I. Same as data-processing equip(cid:173)
`processing system.
`ment. 2. The resources and procedures utilized for data
`processing.
`data processor A computer used for data processing.
`data projector A device which projects the visual output of a
`computer onto a remote screen. Such a device may also ac(cid:173)
`cept inputs for DVDs, HDTVs, S-Videos, and so on. Exam(cid:173)
`ples include DLP projectors and LCD projectors.
`data protection The safeguarding of data against loss, dam(cid:173)
`age, unwanted modification, or unauthorized access. Such
`safeguards may be administrative, physical, or technical.
`Also called data security, protection (2), or infm·mation
`security.
`data rate Same as data transfe1· rate.
`data receiver A point or device, within a communications
`network, that receives data.
`data reception The reception of data over a communications
`network.
`data record A group of related fields, each containing infor(cid:173)
`mation. For instance, a group of fields, each containing one
`of the following items: a name, a corresponding address, and
`a contact number. A collection of data fields form a data re(cid:173)
`cord, and a collection of data records form a file. Also
`called record (2). When used in the context of relational
`databases, also called tuple.
`data recording I. The act of registering, retaining, or saving
`data. 2. Data which has been registered, retained, or saved.
`data recovery I. The salvaging of data stored on a medium,
`such as a disk or a tape, which has been damaged. Such
`damage may be a result of a hardware malfunction, a soft(cid:173)
`ware failure, a power outage, a virus, or physical abuse such
`as the computer falling from a significant height. 2. The
`techniques employed to achieve data recovery (1 ).
`data-recovery system Any system, such as that which in(cid:173)
`cludes preparing, storing, and accessing backup disks or
`tapes, utilized for data recovery (1 ). Also called recovery
`system.
`data reduction The conversion of data into a more useful
`form. For instance, through ordering or summarizing.
`data redundancy The replication of a database, or of any
`portion of it. This may be done, for instance, when a backup
`is desired.