DBMS

Data bases and database systems have become an essential component of everyday life in modern society.

Examples for database Applications:

Purchases from the supermarket
Purchases using your credit card
Booking a holiday at the travel agents
Using the local library
Taking out insurance
Using the Internet
Studying at university
Need to store data :

Data originates at one time and used later(i.e.) Store registrations for grading later, Store for future information needs, Governmental regulations requires access to past data, Data used later for auditing, evaluation purpose, Used more than once : save for future use.

Limitations of manual methods:

Problems of speed, Problems of accuracy, Problems of consistency and reliability, Problems of poor response time, Problems of work-load handling capability, Problems of meeting ad hoc information needs, Problems of cost, Problems due to human frailties: (misplaced) loyalty, inconsistency, irregularity, difficulties in handling big tasks .

Why computerized data processing? Advantage of speed, Advantage of accuracy, Advantage of reliability and consistency, Advantage of storage and retrieval efficiency, Advantage of on-line-access to meet ad-hoc needs, Advantage of cost

Database: Collection of related data. By data, we mean known facts that can be recorded and that have implicit meaning.



Definition of DBMS: A data base management system(DBMS) is a collection of programs that enables users to create and maintain a database. The DBMS is hence a general purpose software system that facilitate the process of defining, constructing , manipulating and sharing databases among the various users and applications.