2.2.3 Database concepts 2.2.3.1. Data
The term data refers to a fact, text, graphics, images, and
videos segments that they have the same meaning in the users' environment. That
could be recorded and stored on computer media. Data are distinct pieces of
information, usually formatted in a special way.
2.2.3.2 Database
The term database means a collection of related data
organized in a way that can be processed by application programs. By organized
we mean that the data are structured so as to be easily restored, manipulated
and retrieved by users. By related we mean that the data describe a domain of
interest to a group of users and that the users can use the data to answer
questions concerning that domain. Database may be of any size and complexity. A
database management system
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(DBMS) consists of a set of licensed programs that define and
maintain the structure of the database and provide support for certain types of
application programs.
2.2.3.3 Database system
Database system is basically a computerized record-keeping; it
is a computerized system whose overall purpose is to store information and to
allow users to retrieve and update that information on demand.
The information in question can be anything that is of
significance to the individual or organization concerned-anything, in other
words, that may be necessary to the decision-making processes involved in the
management of that organization.
2.2.3.4 Database management system
Database management system is the software that handles all
access to the database. A major role of database management system is to allow
the user to deal with the data in abstract terms, rather than as the computer
stores the data.
Database management system is computer program (or more
typically, a suite of them) designed to manage a database (a large set of
structured data), and run operations on the data requested by numerous clients.
Typical examples of DBMS use include accounting, human resources, and customer
support systems. Originally found only in large organizations with the computer
hardware needed to support large data sets, DBMSs have more recently emerged as
a fairly standard part of any company back office.
DBMS's are found at the heart of most database applications.
Sometimes DBMSs are built around a private multitasking kernel with built-in
networking support although nowadays these functions are left to the operating
system.
2.2.4 Data Modelling
Data model is the analysis of data object and their
relationship to other data objects. Is often the first step in database design
as the designers first create a conceptual model of how data items relate to
each other.
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2.2.4.1 Entities
Things or objects of significance to the business, whether
real or imagined about which the business must collect and maintain data, or
about which information needs to be known or held.
2.2.4.2 Attributes
There are properties or characteristics of an entity type that
is of interest to the organization or the entity's characteristics.
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