DBMS–Data Independence | Logical Data | Physical Data Independence

DBMS–Data Independence

• Data independence can be explained using three-schema architecture.
• Data independence refers to being able to modify the schema at one level of the database system, without changing the schema at a higher level.

There are two types of data independence:

1. Logical Data Independence

• Logical data independence refers to the attribute of being able to change the conceptual schema without changing the external schema.
• Logical data independence is used to separate the external level from the conceptual view.
• If we make any changes in the conceptual view of the data, then the user view of the data will not be affected.
• There is logical data independence at the user interface level.

 2. Physical Data Independence

• Physical data independence can be defined as the ability to change the internal schema without changing the conceptual schema.
• If we make any changes in the storage size of the database system server, then the conceptual structure of the database will not be affected.
• Physical data independence is used to separate the conceptual level from the internal levels.
• Physical data independence occurs at the logical interface level.