DBMS-Three Level Architecture

Kirti yadav
NiXiS Institute
Published in
2 min readApr 13, 2020

Three level architecture is also called three schema architecture

what are we going to learn ?

  1. Reason of creation of 3 level architecture.
  2. What is 3 level /schema architecture.

Why is 3 level architecture created ?

Three level architecture was created to keep the physical database separate from the user applications.

Three Level Architecture

What is 3 level architecture ?

This architecture has three levels:

  1. External level
  2. Conceptual level
  3. Internal level

1.External level

  • It is also known as view level.
  • This is highest level architecture and closest to the user.
  • The user doesn’t need to know the database schema details such as data structure, table definition etc.
  • External level is related to the data which is viewed by individual end users.

2. Conceptual level

  • It is also known as logical level.
  • The conceptual level is a higher level than the physical level.
  • This level is maintained by DBA(database administrator).
  • The whole design of the database such as relationship among data ,schema of data etc.are described in this level.
  • It is the middle level between external or internal levels.

3. Internal level

  • It is also known as physical level.
  • This is the lowest level of the architecture.
  • This data is stored in the external hard drives in the form of bits.
  • This level describes how the data actually stored in the storage device.
  • This physical level also discuess encryption techniques.
  • This level is also responsible for allocating space of the data.

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Kirti yadav
NiXiS Institute

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