Information System
1. DBMS
a) Problem with the traditional file environment
In most organizations systems tended to grow independenty without a company-wide plan. Accouning, finance, manufacturing, human resources, and sales and marketing all developed their own systems and data files.
Each application of course, required its own files and its own computer program to operate. For example, the human resources functional area might have personnel master file, a payroll file, a medical insurance file, a pension file, a mailing list file, and so forth until tens, perhaps hundreds, of files and programs existed. In the company as a whole, this process led to multiple master file created, maintained, and operated by separate divisions or departments. As this process goes for 5 or 10 years, the organization is saddled with hundreds of programs and applications that are very difficult to maintain and manage. The resulting programs are data redundancy and inconsistency, program-data dependence , inflexibility, poo data security, and an inability to share data among applications.
Data Redundancy and Inconsistency
Data redundancy is the presence of duplicate data in multiple data files so that the same data are stored in more than place or location. Data redundancy occurs when different groups in an organization independently collect same piece of data and store it independently of each other. Data redundancy wastes storage resources and also leads to data inconsistency, where the same attribute may have different values.
Program-Data Dependence
Program-data dependence refers to the coupling of data stored in files and the specific programs required to update and maintain those files such that changes to the data . Every traditional computer program has to describe the location and nature of the data with which it works. In traditional file environment, any change in a sofware program could require a change in the data accessed by the program. One program might be modified from a
a) Problem with the traditional file environment
In most organizations systems tended to grow independenty without a company-wide plan. Accouning, finance, manufacturing, human resources, and sales and marketing all developed their own systems and data files.
Each application of course, required its own files and its own computer program to operate. For example, the human resources functional area might have personnel master file, a payroll file, a medical insurance file, a pension file, a mailing list file, and so forth until tens, perhaps hundreds, of files and programs existed. In the company as a whole, this process led to multiple master file created, maintained, and operated by separate divisions or departments. As this process goes for 5 or 10 years, the organization is saddled with hundreds of programs and applications that are very difficult to maintain and manage. The resulting programs are data redundancy and inconsistency, program-data dependence , inflexibility, poo data security, and an inability to share data among applications.
Data Redundancy and Inconsistency
Data redundancy is the presence of duplicate data in multiple data files so that the same data are stored in more than place or location. Data redundancy occurs when different groups in an organization independently collect same piece of data and store it independently of each other. Data redundancy wastes storage resources and also leads to data inconsistency, where the same attribute may have different values.
Program-Data Dependence
Program-data dependence refers to the coupling of data stored in files and the specific programs required to update and maintain those files such that changes to the data . Every traditional computer program has to describe the location and nature of the data with which it works. In traditional file environment, any change in a sofware program could require a change in the data accessed by the program. One program might be modified from a