Data Abstraction: Different users require different view of the database which is useful and necessary to them. This is data abstraction by which we abstract useful data from a database for a particular type of users to use.
There are 3 levels of data abstraction, those are as follows;
- Physical Level: The lowest level of abstraction describes how the data are actually stored. The physical level describes complex low level data structures.
- Logical Level: This level of abstraction describes what data are stored in the database and what relationships exist among those data. Thus it also describe structures but separating them in small parts.
- View Level: This level represents only a part of the entire database. Even though logical level is simpler than physical level, view level is required because a database may have tons of data all of which are not useful to all users.