Question

Discuss the concept of data independence and explain its importance in a database environment.

Answer 1

ANSWER :

Data independence is ability to modify a schema definition in one level without affecting a schema definition in the next higher level.

There are two levels of data independence:

1.Physical Data Independence
2.Logical Data Independence

>>Physical Data Independence :
Physical Data Independence is defined as the ability to make changes in the structure of the lowest level of the Database Management System (DBMS) without affecting the higher-level schemas. Hence, modification in the Physical level should not result in any changes in the Logical or View levels.

>>Logical Data Independence :
Logical data is data about database, that is, it stores information about how data is managed inside. For example, a table (relation) stored in the database and all its constraints, applied on that relation.
Logical data independence is a kind of mechanism, which liberalizes itself from actual data stored on the disk. If we do some changes on table format, it should not change the data residing on the disk.

Importance :

* Encourages you to improve the nature of the information

* Implementation of principles and improvement in database security

* Effectively make adjustments in the physical level is expected to improve the exhibition of the framework.

* It allows you to improve state which is undamaged or undivided

* You don't need to alter data structure in application programs

* Database incongruity is vastly reduced