What is completeness constraint on generalization, Database Management System

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What is completeness constraint on generalization? Define the variation between total and partial design constraint. Give an example each.

Ans: Completeness Constraints

1. Total specialization constraint

a. Each entity in the superclass should be a member of some subclass in the specialization for example {HOURLY_EMPLOYEE, SALARIED_EMPLOYEE}

b. Notation: superclass

2. Partial specialization constraint an entity might not belong to any type of the subclasses

For example: {SECRETARY, ENGINEER, TECHNICIAN}

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