3.8. Describe the two alternatives for specifying structural constraints on relationship types. What are the advantages and disadvantages of each?

CARDINALITY RATIO AND PARTICIPATION

ADVANTAGE

CARDINALITY RATIO

(THEY ARE USED TO SIMPLIFY DESIGNS)

DISADVANTAGE OF CARDINALITY RATIO IS THAT

(YOU CAN NOT SPECIFY A GIVEN NUMBER TO BE MAXIMUM)

ADVANTAGE OF PARTICIPATION CONSTRAINT IS THAT

(IT SHOWS WETHER THE EXISTENCE OF AN ENTITY IS DEPENDENT ON ITS RELATIONSHIPS WITH ANOTHER ENTITY)

DISADVANTAGE OF PARTICIPATION CONSTRAINT

(IT IS A COSTLY AFFAIR USING BOTH MODELS TO EXPRESEE RELATIONSHIPS).

Explanation:CARDINALITY RATIO specifies that maximum number of relationships an entity can engage itself in.

Participation constraint is a constraint that

Specifies whether the existence of an entity depends on its Relationships to another entity, it specifies the the minimum number of relationship instances that an entity can participate in

It is also minimum cardinality constraint,it has two types named as Total participation and partial participation.