A Database Management System (DBMS) is a collection of software or program which help user in creation and maintenance of database. Hence it is also known as computerized record-keeping system. Database Management System is the software system that helps in the process of defining, constructing and manipulating the database.
Database Management System has become an integral part of the information systems of many organizations as it is use to handle a huge amount of data.
Computer-based Information System (IS) is capable of serving many complex tasks in a coordinated manner. Such systems handle large volumes of data, multiple users and several applications in a centralized database environment.
The Heart of an Information System (IS) is Database Management System. This is because most Information Systems (IS) have to handle huge amounts of data. This core module of an Information System is called as Database Management System (DBMS).
Characteristics of Database Management Systems
The database approach has many important characteristics due to which database has become an integral part of the software industry. The various characteristics of the DBMS are as follows:
(1) Data Integrity
Integrity constraints provide a way of ensuring that changes made in the database by authorized users that do not result in the loss of data consistency and correctness. Database integrity is concerned with the correctness and completeness of data in the database.
This objective can never be guaranteed, one cannot ensure that every entry made in database is accurate.
(2) Data Security
A Database Management System always has a separate system for security which is responsible for protecting database against accidental or intentional loss, destruction or misuse.
Data in database should be given to only authorize users. Only authorized users should be allow to modify data. Authorized users are able to access data any time he wants.
(3) Data Independence
Data Independence can be define as the capacity to change data kept at one place without changing data kept at other locations.
(4) Transaction Control – Rollback
The changes made in the database can be revert back with the help of rollback command. The changes can be save successfully with the help of commit data command.
(5) Concurrency Control
The data in the database can be access by multiple users at same point of time. Such operations are allow by sharing same data between multiple users. This is nothing but we can say that concurrency control.
(6) Data Recovery – Backup and Restore
Database recovery is the process of restoring the data to original (correct) state after database failure. The main element of database recovery is the most recent database backup.
If you maintain database backup efficiently, then database recovery is very straight forward process.
(1) Naive Users
Naive users are users who interact with the system using application programs that have been develop previously. The typical graphical user interface for naive users is a kind of form interface, where the user can fill in appropriate fields of the form. Naive users can read reports generated from database.
(2) Application Programmers
Application programmers responsible for writing application programs that use the database. Application programmers are developers or computer professionals who write application programs. It develop user interfaces using any preferred language.
Rapid Application Development (RAD) tools are available nowadays that enable an application programmer to construct application without writing code.
(3) Sophisticated Users
Sophisticated users interact with application without writing programs by using a database query language. This query will be solve by query processor.
Online Analytical Processing (OLAP) tool is use to view summaries of data in different ways which helps analysts with OLAP analysis can use data mining tools, which help them to find certain kinds of pattern in data.
(4) Specialized Users
Specialized users creates the actual database and implements technical controls needed to enforce various policy decisions. Specialized users are sophisticated users who develop database applications.
The Database Administrator (DBA) is also responsible for ensuring that the system operates with adequate performance and for providing a variety of other related technical services.