Page 51 - DLIS408_INFORMATION_TECHNOLOGY-APPLICATIONSL SCIENCES

Information Technology and Application

Notes The literature published on the subject of databases in the field of library and information science
tends to focus on the use of online search services and searching techniques. There is not much
clearly identifiable literature on the creation and management of textual databases covering the
procedural aspects of building and managing information packages consisting largely bibliographic
information. This section outlines the concept of database, issues related to its need and its
composition.

Different Approaches to Database

In the literature of computer science, one encounters a number of definitions for the term database.
Let us examine some of the definitions so as to understand different approaches to this concept.
(i) “A collection of data on a defined range of subjects together with all the information
needed to access that data”.

(ii) “A named collection of units of physical data which are related to each other in a specific
manner”.
(iii) “A generalised, common integrated collection of (company or installation owned) data
which fulfils the data requirements of all applications which exist in an enterprise”.
(iv) “The term database refers to just the information file. Database software is the set of
programs whose function is to manage the data and programs that operate on it. The
database system is the entire hierarchy of elements, files and application programs that
result in efficient management of information”.
(v) “A database is a collection of data organised in a manner which allows retrieval and uses
that data by anyone needing it. A database is organised and designed to allow a large
number of users to draw information from it for many purposes in many different for-
mats”.
(vi) “In its most basic form, a database consists of a number of data elements, each of which is
a unit of data that is complete in itself. A part number for example, is a typical data element.
These elements are organised into logically related groups called data structures. The data
files in database system are organised in a fashion that permits their use in several appli-
cations rather than a single application. Thus, in a database system the focus shiftsfrom a
particular application and its specific input and output needs to a more general require-
ment for the data files to serve a number of applications’.
It may be noted that each of the above definitions regards the ‘database’ from a different view
point, its access, purpose, description, contents and integration. Yet, each refers to a specific collection
of organised data rather than any data on computer-readable media. The last mentioned definition
is a comprehensive one, which clearly explains the concept of a database and also brings out the
essential difference between a database and a traditional computer file. This definition also refers
to a database system. It is important to distinguish the term database from the term database
system, all the components of which cooperate to collect, manipulate, manage and deliver
information.

Database Features
One of the main purposes of a database is that the data in the database should be used for a variety
of different applications. To achieve this it is important for a database to possess the following
features:
it must be substantially non-redundant (that is to say that the database should not have
duplication of data) because duplication of data leads to difficulty in ensuring data consis-
tency, and results in the wastage of storage space:
it must be program-independent so that the data can be moved or restructured without the
need to make alterations to programs. This concept is known as ‘data independence’;
it must be capable of being used by all programs;

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