An Online Web Application For News Around The School

2.3    Database
In the early days of computerization, it was normal to maintain specific files for individual applications. Data were processes centrally in batches and there was little or no online interrogation of data. This approach is wholly inefficient for most of today’s data processing systems. Supporting this, Vossen (1991) enumerated the problems that result from organizing data using the file system:
a)        There exists a high redundancy between files, which result from the fact that the information is replicated in different places, and that these replications are not controlled by a central monitor.
b)        Inconsistencies might result from the possibilities that a program makes changes on the files it uses without these changes being made (at the same time) by all other programs that uses the file.
c)        There exists inflexibility against changes in the application: if new actions or events arise in the course of time, these can be realized at a substantial expense of time.
d)        The work of many programmers involved is characterized by low productivity, since program maintenance is expensive: if the structure of an existing file has to be modified during its lifetime, then all application programs have to be modified correspondingly.
e)        Finally, there is the problem of adopting and maintaining standards (with respect to coding, data formats, etc.), which is important for exchanging data or for migration to a new operating system release, or even to a new computer system.
To overcome these problems, databases were developed. It is now common for large organizations to organize their operational data using the database technology.
The subject of database is adequately covered in many works on database technology. Clifton (1983) briefly defines database as a collection of data supporting the operation of an organization. Quoting CIMA, Lucey (1991) provides a more detailed definition:
A database is a file of data structured in such a way that it may serve a number of applications without its structure being dictated by any one of those applications, the concepts being that programs are written round the database rather than files being structured to meet the needs of particular programs.
Russell, M. (1987) dealt extensively on the need for the use of computers on such database system like computerized clearance system.
In the words of Dimorji (2003),
“At the center of any information system is a database, which is any collection of related information grouped together as a simple item. The term can also apply to the ways in which information is catalogued, analyzed, stored and used manually”.
Russell (2005) was also of the view that without a computer, effective handling of Candidates’ records cannot be achieved effectively.
In a database, all the data is defined together rather than each file being defined separately. In fact, all the literature consulted seems to support the fact that a database is a collection of structured data with the structure of data being independent of any particular application. Specifying the need for databases, O’Leary (1996) listed the following advantages:
a)        Sharing: In an organization, information from one department can be readily shared with others.
b)        Security: Users are given passwords or access only to the kind of information they need to know. Thus, the Payroll department may have access to employees’ pay rate, but other departments would not.
c)        Fewer Files: With several departments having access to one file, there are fewer files. Therefore, excess storage or what is called ‘redundancy’ is reduced.
d)        Data Integrity:    Older filing systems many times did not have ‘integrity’. That is, a change made in the file in one department might not be made in the file in another department. As one might expect, this can cause serious problems and conflicts when data is used for important decisions affecting both departments.