Database Management System: Unit I: Relational Databases

Data Independence

Relational Databases - Database Management System

Data independence is an ability by which one can change the data at one level without affecting the data at another level. Here level can be physical, conceptual or external.

Data Independence

Definition: Data independence is an ability by which one can change the data at one level without affecting the data at another level. Here level can be physical, conceptual or external.

Data independence is one of the important characteristics of database management system.

By this property, the structure of the database or the values stored in the database can be easily modified by without changing the application programs.

There are two types of data independence

1. Physical Independence: This is a kind of data independence which allows the modification of physical schema without requiring any change to the conceptual schema. For example - if there is any change in memory size of database server then it will not affect the logical structure of any data object.

2. Logical Independence: This is a kind of data independence which allows the modification of conceptual schema without requiring any change to the external schema. For example - Any change in the table structure such as addition or deletion of some column does not affect user views.

By these data independence the time and cost acquired by changes in any one level can be reduced and abstract view of data can be provided to the user.

Database Management System: Unit I: Relational Databases : Tag: : Relational Databases - Database Management System - Data Independence