Proprietary systems Systems (usually referring to operating
systems) that are the property of a particular software vendor and,
in most cases, were written expressly for a particular computer
system. Examples are Windows 7, which is Microsoft’s current
operating system for personal computers, and z/OS and z/VM,
which are two alternative large machine operating systems
offered by IBM.
Prototyping A systems methodology in which an initial
version of a system is built very quickly using fourth generation
tools and then is tried out by users, who recommend changes that
are the basis for building an improved version. This iterative
process is continued until the result is accepted. See alsoRapid
application development.
Pull technology Refers to the mode of operation on the
Internet where the client must request data before the data are
sent to the client. For example, a Web browser represents pull
technology in that the browser must request a Web page before it
is sent to the user’s screen. See alsoPush technology.
Push technology Refers to the mode of operation on the
Internet where data are sent to the client without the client
requesting the data. Examples of push technology include
electronic mail and the distribution of software updates to the
client.See alsoPull technology.
Quad-core processor A processor chip that has four complete
processors manufactured as part of a single chip. There are also
dual-core, 6-core, and 8-core processors in use, and there will
eventually be 16-core and larger processor chips. See also
Multiprocessor.
Query language A 4 GL, nonprocedural special-purpose
language for posing queries to the database, often built into the
DBMS, that allows users to produce reports by specifying their
content and format.
RAD SeeRapid application development.
Radio frequency identification (RFID) A growing approach
to item identification employing RFID tags—often the size of a
postage stamp or smaller—that combine tiny chips with an antenna.
When a tag is placed on an item, it automatically radios its
location to RFID readers on store shelves, checkout counters,
loading bay doors, and possibly shopping carts. With RFID tags,
inventory is taken automatically and continuously. RFID tags can
cut costs by requiring fewer workers for scanning items; they can
also provide more current and more accurate information to the
entire supply chain.
Rapid application development (RAD) A hybrid systems
development methodology based upon a combination of SDLC,
prototyping, JAD techniques, and CASE tools, in which the
end-prototype becomes the actual system. See alsoPrototyping,
Joint application design, CASE.
Raster-based GIS One of two basic approaches for represen-
tation and analysis of spatial data in which space is divided into
small, equal-sized cells arranged in a grid; these cells (or rasters)
can take on a range of values and are “aware” of their location
relative to other cells. Weather forecasting employs a raster-
based approach.
Reduced instruction set computing chip SeeRISC chip.
Relational DBMS A particular type of database management
system (DBMS) that views each data entity as a simple table,
with the columns as data elements and the rows as different
instances of the entity. The records are then related by storing
common data, for example, customer number, in each of the
associated tables. Relational DBMSs are the most popular type of
DBMS today.
Relationship A relevant association between organizational
entities, such as a customer (entity) submits (relationship) an
order (entity).
Release management A documented process for migrating a
new system, or a new version of an older system, from a develop-
ment environment to a production (operations) environment
within a given organization.
Remote login An Internet application that permits a user to log
into and perform work on a computer that is remote to the user’s
current location.
Request for proposal (RFP) A document that is sent to
potential vendors inviting them to submit a proposal for a system
purchase. It provides the objectives and requirements of the
desired system, including the technical environment in which
it must operate; specifies what the vendor must provide as input
to the selection process; and explains the conditions for sub-
mitting proposals and the general criteria that will be used to
evaluate them.
Reverse auctions An online auction in which sellers lower
their prices in response to competitors’ bids in order to “win” a
purchase contract with a customer.
RFID SeeRadio frequency identification.
RFP SeeRequest for proposal.
Ring topology A network topology in which all network
devices share a single length of cable—with the ends of the cable
connected to form a ring.
Ripple effect The result that occurs when a change in one part
of a program or system causes unanticipated problems in a
different part of the program or system. Then changes necessary
to correct that problem may cause problems somewhere else,
and so on.
RISC chip Very fast processor chip based on the idea of
reduced instruction set computing, or RISC; originally developed
for use in high-powered workstations, but now used in other
machines, especially midrange systems.
Risk management A term used to refer to activities directed at
successfully managing risks to an organization. For example,
organizations need to assess the potential business-related losses
associated with the implementation of new computer solutions as
well as computer, software, and network failures of various types
to determine how best to manage a software development project
and the amount to spend on security technologies and procedures
that decrease the likelihood of significant business losses.
Router A hardware device employed in a telecommunications
network to connect two or more local area networks (LANs),684 Glossary