Schema and Three Level Schema

Schemas: 

Schema is Blueprint or Visualization of the data into Database that show how the data to be store in the Database and How the relationship of  each other.

Student

Student_id

Student_name

Student_mobile_no

Course

Course_Id

Course_Name

Student_id

 

 

 

Three Level Schema Architecture:  

1.     View Level: In this level user can interact through the application. User can store and retrieve the information/ Data through the data base. Many persons access the database using any application. This Level is also called the External Level.

2.     Logical Level: This Level also called a Conceptual Level. This Level provides a logical view for the user that user easily to understand how the data to be store in the database. It show the data in a tabular form.

3.   Physical Level: This Level is also called to Internal Level.  This Level store the data in Database in the file form and this level is also help to which data to be store and where in the database.