Define the concept of aggregation. Give two examples of where this concept is useful.

Q) Define the concept of aggregation. Give two examples of where this concept is useful.

Answer: Aggregation is an abstraction through which relationships are treated as higher-level entities. Thus the relationship between entities A and B is treated as if it were an entity C. Some examples of this are:

a. Employees work for projects. An employee working for a particular project uses various machinery. See Figure

E-R diagram Example 1 of aggregation.

b. Manufacturers have tie-ups with distributors to distribute products. Each tie-up has specified for it the set of products which are to be distributed. See Figure

E-R diagram Example 2 of aggregation.

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