A database is an organized collection of logically related data. It consists of 4 elements.
- Data items are the binary computer representations of the stored logical entities.
- Constraints are the predicates that the define correct states of database.
- Relationships which can explain the correspondence relation between the various data elements.
- Schema which explains the organization of data and the relationships within the database structure.
DATABASE MANAGEMENT SYSTEM:
In the year 1960 first database management system was introduced and usage of database is further evolved in next few years. Before database management systems are introduced there are problems with file processing systems
Definition of DBMS:
A database management system (DBMS) is a best collection of programs that enables the users to create and maintain the database. Basic functionalities of database management system is to manipulate, construction and defining database for different applications.
Role of DBMS:
The DBMS works like a mediator between the user and the database. The database structure is the complete accessed itself is stored as a collection of files, and the way only to access the data in those files is through the Data Base Management System.
Types of DBMS:
DBMS can support many different types of databases. But the classification according to the number of Users, the database locations and the expected type and extent of use.
1) Single-user
2) Multi-user.
COMPONENTS OF DBMS:
A database system is more than just data or data in combination with database management software. A complete data system in an organization consists of four components:
1) Hardware.
2) Data.
3) Software.
4) People.
ADVANTAGES OF DBMS:
The primary advantages are:
1) Program data-independence
2) Minimal data redundancy
3) Improved data consistency
4) Improved data sharing.
5) Improved data accessibility and responsiveness.
6) Improved data quality.
7) Increased productivity of application development.
8) Reduced program maintained.
9) Providing back-up and recovery.
10) Restricting unauthorized access
DISADVANTAGE of DBMS:
1) Confidentiality
2) Danger of a Over Kill.
3) Data Quality.
4) Data Integrity.
5) Enterprise Vulnerability.
6) Qualified Personnel.
7) The Cost of Using a DBMS.
Download Introduction to Database Management Systems .