Concepts Of DBMS


Database and database system have become an essential component of everyday life in modern society.In the course a day,most of us encounter several activities that involves some interaction with a database.For example, if we go to the bank to deposits or withdraw funds;if we make a hotel or railway reservation; if we access a computerized library catalog to search for a book; or if we order a magazine subscription from publisher,chances are that our activities will involve someone accessing a database. Even purchasing items a supermarket nowadays in many cases involves an automatic update of the data base that keeps the inventory of supermarket items.A database may be generated and manipulated manually or itmay be computerized.

Database and DBMS

A database system is basically a record keeping system.It may also be defined as a collection of interrelated data stored together to serve multiple applications,where the data are stored in a common and controlled manner so that they are independent of the programs that use the data. Also addition of new data, retrieval of existing data, modification and/or deletion of data can be made easily and efficiently within database. Database in simplest words is a structured repository of data needed for the functioning (data processing) of an organization. A Database Management System (DBMS) is a collection of programs that enables users to create and maintain database. The DBMS is hence a general purpose software system that facilitates the process of defining, constructing, and manipulating databases for various applications.Defining a database involves specifying the data types, structures, and constraints for the data to be stored in the database. Constructing the database is the process of storing the data itself on some storage medium that is controlled by the DBMS. Manipulating a database includes such functions as querying the database to retrieve specific data, updating the database to reflect changes, and generating reports from the data.

Advantages of Databases

1. Databases reduce the data redundancy to a large extend.

2. Database can control data inconsistency to a large extend.

3. Databases facilitate sharing of data.

4. Databases enforce standards.

5. Databases can ensure security.

6. Integrity can be maintained through databases.

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