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Three Level Database Architecture

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Three Level Database Architecture

The Three level database architecture, also known as the three level of Abstraction which is concerned to schema. The word Schema means structure, either any website like (Amazon or flip-kart) stores the data in any format and they have defined a structure. Three schema means With respect to the ANSI/SPARC three level database architecture in dbms is defined as follows.

What is Schema:

Example: We have data roll no, name, marks we are going to store that data in table.  In this condition our schema or structure in the form of Table.

External Level of Database Architecture:

External level, view or schema is used to store the definitions of different views in order to support different user groups.

Those views are provide data help from database how it is flowing. Then a programmer make program according to them.

Conceptual Level of Database Architecture:

Conceptual level, view or schema is used to store the structure of whole database of the organization. User groups does not deal with conceptual schema. Only DBA (Database Administrator) who deals with conceptual schema.

Schema of Database:

Schema defined at conceptual level is also stored at Internal level, view or schema by adding some more useful information. This extra added information is helpful for DBMS for accessing and storing data physically. So internal level, view or schema is used by DBMS.

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