Week 12: DBMS

DBMS stands for "Data Base Management System". It is software that defines a database, stores the data and supports a query language, produces reports, and creates data entry forms.

Examples of DBMS software: MS-Access, MySQL, Oracle and FoxPro

Advantages of DBMS 

Advantages	Explanation
1.Controlling Data Redundancy	Avoid duplication of same data in different files and wastage of storage space. Reduce the time to keep the same data.
2. Elimination of Inconsistency	Remove the duplication of data in multiple file to eliminate inconsistency.
3. Better service to the users	Centralizing the data in the database so that user can obtain new and combined information easily
4. Flexibility of the System is Improved	Changes are made more easily in a centralized database
5. Integrity can be improved	DBMS used by a number of users at a time. It is essential to enforce integrity-constraints.
6. Standards can be enforced	Standardizing stored data formats is usually desirable for the purpose of data inter¬change or migration between systems.
7. Security can be improved	Different checks can be established for each type of access (retrieve, modify, delete etc.) to each piece of information in the database.
8. Organization's requirement can be identified	It is the responsibility of the DBA (Database Administrator) to structure the database system to provide the overall service that is best for an organization.
9. Overall cost of developing and maintaining systems is lower	It is much easier to respond to unanticipated requests when data is centralized in a database . The cost of  developing and maintaining DBMS application programs to be far lower than for similar service using conventional systems.
10. Provides backup and Recovery	Centralizing a database provides the schemes such as recovery and backups from the failures including disk crash, power failures, software errors which may help the database to recover from the inconsistent state.

Disadvantages of DBMS

Advantages	Explanation
1. Added expense	to acquire the software for DBMS
2. More hardware may be needed	if there is any increase in data
3. Data Back up	If it crashes, complexity of backup and recovery
4. Additional training	Sophisticated design and programming required
5. No guarantee on data security	data may be viewed by irresponsible individual as the data may get hacked