Data abstraction in DBMS is the process of hiding irrelevant or unimportant details from the end user to make accessing data easier and more secure. It provides a different view of the data and helps achieve data independence, which enhances data security. Database systems are complex, and data abstraction simplifies database design by reducing complexity in terms of usability for users and making the system efficient in terms of data retrieval.
There are three levels of data abstraction in DBMS:
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Physical or Internal Level: This is the lowest level of abstraction, which defines how the data is actually stored in the database. It defines data structures to store data and access methods used by the database. It is decided by developers or database application programmers how to store the data in the database.
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Logical or Conceptual Level: This is the middle level of abstraction, which describes what data is stored in the database. It describes the relationship among data and how it is implemented logically. Programmers generally work at this level because they are aware of such things about database systems.
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View or External Level: This is the highest level of abstraction, which describes the user interaction with the database system. It defines different views that define the parts of the overall data of the database. Users can access data based on their queries at this level.
In summary, data abstraction in DBMS is a process of hiding irrelevant details from the end user to make accessing data easier and more secure. It simplifies database design and enhances data security. There are three levels of data abstraction in DBMS: Physical or Internal Level, Logical or Conceptual Level, and View or External Level.
