Aggregation in DBMS

What is Aggregation in DBMS ?

Aggregation:

An ER diagram is not capable of representing relationship between an entity and a relationship which may be required in some scenarios. In those cases, a relationship with its corresponding entities is aggregated into a higher level entity. 

For example, Employee working for a project may require Machinery .

So, REQUIRE relationship is needed between relationship WORKS_FOR an entity MACHINERY.  

Using aggregation , WORKS_FOR relationship with its entities, EMPLOYEE and PROJECT is aggregated into single entity and relationship REQUIRE created between aggregated and  MACHINERY.

Conclusion-

These were some of the point discussed in the post- Aggregation in DBMS.

There is more coming with the next post keep reading...