3 level architecture of DBMS System


3 Level Architecture of Database System

DBMS works as query optimizer so DBMS architecture is divided into 3 level architecture of DBMS System for accepting data from user, process on data and save data in to database finally.

3 Tier DBMS Architecture

The DBMS 3 tier architecture represent the whole process about query processing from user to database.DBMS architecture divide in 3 level-

  1. External Level

  2. Conceptual Level

  3. Physical Level

1. External Level-

That level also called as Top Level. In that level the end user and application view is only present. That stage also called “view” stage because in that level only user interact with application. The front-end of any DBMS software presents here only.That level also called as Data Abstraction Level.

User don’t need to understand working about query optimization they only need about complete their task. In that level only user interact with application.

2.Conceptual Level-

That level is important for query execution. Conceptual Level is totally responsible for database management, schema management, table relationship operations. All constraints apply on data in that stage also. All DML, DDL commands execution in that level. In that level also checks authentication of user and also gives validations about data.Conceptual Level called as Middle level also.

The DBA (Database administrator) team interact with that level and working done for query processing.

3.Physical Level-

In that level actual data stored, That level actual responsible for hows data can be stored on computer. The all database files are stored here successively. The database stored in secondary devices in that stage. Physical level also called as low level of DBMS architecture.





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