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Unformatted text preview: irect file: A file organization in which the desired record (piece of information)
can be directly located by its key field value without having to search through a
sequence of other records. Also known as random file.
Direct Memory Access (DMA) architecture: An architecture which leads to
more efficient CPU utilization because the I/O request is largely processed by the
DMA controller without direct participation of the CPU.
Direct/leased-Iine connection: A method of connecting a computer to the Internet
by using a dedicated (leased) telephone line.
Directory: A mapping table used by operating systems to map file names to their
corresponding file attributes and file data, and also to provide greater flexibility to
users in file naming.
Disaster recovery: Policies and mechanisms adopted by an organization to protect
valuable data from getting lost in case its main computing facility is destroyed by
a natural calamity.
A copy of all valuable data is continuously created
on a storage system that is geographically far apart from the main computer
system. In case of a disaster, the data is recovered from this copy.
Disk: A flat, circular plate coated with a magnetic material on which data can be
stored by magnetization of portions of the flat surface.
Disk array: A mass storage device, which uses a set of hard disks and hard disk
drives with a controller mounted in a single box. All the disks of a disk array form
a single large storage unit. Also known as Redundant Array of Inexpensive Disks
Disk drive: A devise used for storage and retrieval of data stored on disk.
Disk pack: A removable direct-access storage medium containing multiple
magnetic disks mounted vertically on a single shaft. Diskette: A low-cost, thin, flexible magnetic disk storage device used on small
computer systems. Also called a floppy disk.
Distributed computing system: A computer system consisting of interconnected,
Distributed database: Seamless integration of multiple databases located on
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This document was uploaded on 04/07/2014.
- Spring '14