Why DBMS ?
Data is one of the most important assets of a business. It is very important to make
sure data is stored and maintained accurately and quickly. DBMS (Database
Management System) is a system that is used to store and manage data.

A DBMS is a set of programs that is used to store and manipulation data.

Manipulation of data :

Adding new data.

Deleting unwanted data
Changing existing data

A DBMS provides functions for data security, data integrity, data sharing, data
concurrence, data independence, data recovery etc.

DBMS are designed to support large amount of data.

Data Sharing and Concurrency

Data sharing
Same data can be accessed by two or more users.

Data concurrency
The same data can be accessed by multiple users at the same time .
DBMS locks data to avoid tw ousers from modifying the same data at the same time.

Data Security
DBMS ensures that data in only accessed by authorized users.
By default, the data of a user cannot be accessed by other users unless the owner gives permissions to other users to do so.

Data Integrity
If data loses integrity, it becomes unusable and garbage. DBMS provides means to implement rules to maintain integrity of the data.

Three integrity rules domain, entity and referential supported by DBMS.

Fault tolerance and recovery
DBMS continue to run in spite of errors, if possible, allowing users to rectify the mistake in the mean time. DBMS allows recovery of data in the event of failure.

Support for Languages
DBMS supports a data access and manipulation language. The most widely used data
access language for RDBMS (relational database management systems) is SQL.

The Advantages of DBMS
1. Improved data sharing
2. Improved data security
3. Better data integration
4. Minimized data inconsistency
5. Improved data access
6. Improved decision making
7. Increased end-user productivity

Disadvantages
Price / Costs / Hardware
Upgrades
Complexisity
Special Staff
Data Security