Data Abstraction Levels OR Explain Data organisation OR View of Data : –
A major purpose of a database system, user with an abstract view of data it means the system hides certain parts of how the data are stored and maintain. The data abstraction is a mechanism that hides in a complexity. There are 3 levels of data abstraction, (1) Physical Level, (2) Logical Level and (3) Conceptual/View Level.
Physical Level: –
- The lowest level of abstraction this level describes how the data are actually stored at the physical level. Complex low level data structures are describe in detail.
Logical Level: –
- It is a middle level abstraction. this level describes how data are actually stored at Logically.
- It is a middle level abstraction. This next level of abstraction describes what data stored in a database and what relationship exists among data. The entire database is described in terms of a small number of simple structures. The implementation of the simple structure may involve complex physical level structure but the user is not aware of this complexity.
Conceptual/View Level: –
- The highest level of abstraction describes only the part of the entire database.
- This Level Describe The Main Features of Database here View Level means How Database Structure is Looking.