Data Abstraction and Levels

Data Abstraction is used to simplify the database design.Database abstraction layers reduce the complexity by providing a level of work to developer and hide the database specifics behind the interface as much as possible.

The level of work can be divided into three part as follows:-

1)Physical Level
2)Logical Level
3)View Level

Physical Level : The level of abstraction which is known as physical level describes How the data are actually stored. This level is also known as Internal or Lowest level.

Logical Level : The next-higher level of abstraction which is known as logical level describes What data are stored in the database, and What Relationships exist among those data.This level is also known as Conceptual or Middle level.

View Level : The highest level of abstraction which is known as view level describes only part of the entire database.This level is also known as External level.