In the first unit of this block, you have been given with the details of the Database Management System, its structure, advantages etc. This unit is an attempt to give you information about E-R models and relational. The relational model is a widely used model for DBMS execution. Most of the commercial DBMS products available in the industry are relational at core. In this part we will talk about the operators, terminology and operations used in relational model.

The second model discussed in this section is the E-R model, which mostly is a semantic model and is very essential in creating raw database design that can be further normalised. We talk about DBMS E-R diagrams, and their conversion to tables in this part.

After Reading this unit, you should be able to:

• Explain relational model and its advantages;

• Execute basic operations using relational algebra;

• Illustrate an E-R diagram for a given problem;

• Change an E-R diagram to a relational database and vice versa.