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The Relational Model and Data Normalization

1. Define functional dependency and give an example.

2. What are insertion and deletions anomalies?

3. List and briefly describe first, second and third normal form.

4. Describe a one-to-one relationship.

5. Describe the many-to-many attribute relationship.

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Question 1.

A functional dependency is a relationship between or among attributes. If we are given the value of one attribute, we can obtain the value of another attribute. For example, if we know the social security number of a student, we can look up the student's name. Student Name is therefore functionally dependent on their social security number. In general terms, attribute A is functionally dependent on attribute B if the value of B determines the value of A: if we know the value of A, we can obtain the value of B.

Question 2.

A deletion anomaly is when, by deleting the facts about one entity, we inadvertently delete facts about another entity; with one deletion, we lose facts ...

Solution Summary

The Relational Model and Data Normalization points are highlighted.