Page 50 - DLIS408_INFORMATION_TECHNOLOGY-APPLICATIONSL SCIENCES

Unit 4: Database

Self Assessment Notes

Multiple choice questions:
3. DBMS stands for:
(a) Database Management system
(b) Digital Mapping system
(c) Data Borrowing and Movement Software.
(d) Database Manipulation Software.
4. Three types of people are involved with a general-purpose.....
(a) Microsoft’s SQL server (b) Microsoft’s Access
(c) DBMS (d) Oracle corporation’s oracle.

4.4 Database Approach
Traditionally, data accessed through computers has been stored on different storage media in the
form of individual files. Files proved to be quite satisfactory so long as computerisation was
limited to a few application areas and use of computers is restricted. However, as the actual users
grew in number, with the advent of online sharing systems, the file systems gave rise to many
serious problems. The discipline of database systems evolved in response to these problems.
It may be emphasised that the database approach is more than merely a different computer
technique involving the storage of data and the use of additional generalised software. It involves
a new approach to designing and operating information systems throughout the enterprise and
can have far reaching effects beyond the data processing department. Stated differently, database
approach regards data as a resource to be managed along with more generally recognised resources
of an organisation (such as staff, finance, equipment and premises) so as to be available to a variety
of applications and users. The integrated database is intended to provide a consistent view of the
institution’s/enterprise’s data for all user departments. Although, each department has
responsibility for specific data, several departments using the same type of data can operate on the
same data values. In other words, a parochial view of data would be discouraged and the
uncoordinated exchange of information among departments would not be necessary. Instead, all
basic data would be input to the database by each department responsible for it and retrieved
(possibly in summarised form) by those departments needing access to it.
The database approach is not dependent on any particular structure of data; many of these concepts
can be applied to files as well. The database approach cannot be practically implemented in the
absence of a computer. In many respects database approach is characterised by the word efficiency.
In principle, one can do any thing with non-database systems as with database systems. In practice,
the cost of doing certain things without the benefit of the database approach is so prohibitive that
the possibility is dismissed. The two main contributors to prohibitive cost are the data redundancy
and the uncontrolled searching time. The database approach is beneficial when online access to
data is provided. With online access, the collection of data and extracting of timely reports becomes
fairly straightforward as the restrictions or delays of batch processing are not imposed on the user.
However, it may be emphasised that the database approach is rooted in the attitude of: sharing
valued data resources; releasing control of those resources to a common responsible authority.

Database Definition

The major problem one faces in the study of database technology relates to the determination as to
what precisely constitutes a database. The casual use of the term database tends to refer to any
organised collection of data capable of being accessed by a computer. This could be applied to a
couple of reels of magnetic tape or a few boxes of punched cards (obsolete now) or a collection of
floppies containing data. As such, this interpretation does not constitute a precise definition for the
concept.

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