Logical Database Design – General Questions

1. The entity integrity rule states that:

A. no primary key attribute may be null.
B. no primary key can be composite.
C. no primary key may be unique.
D. no primary key may be equal to a value in a foreign key.

Correct Answer: A. no primary key attribute may be null.

2. When mapping a many-to-many unary relationship into a relation which of the following is true?

A. One relation is created.
B. Two relations are created.
C. Three relations are created.
D. Four relations are created.

Correct Answer: B. Two relations are created.

3. If no multivalued attributes exist and no partial dependencies exist in a relation, then the relation is in what normal form?

A. First normal form
B. Second normal form
C. Third normal form
D. Fourth normal form

Correct Answer: B. Second normal form

4. A foreign key is which of the following?

A. Any attribute
B. The same thing as a primary key
C. An attribute that serves as the primary key of another relation
D. An attribute that serves no purpose

Correct Answer: C. An attribute that serves as the primary key of another relation

5. A transitive dependency is which of the following?

A. A functional dependency between two or more key attributes.
B. A functional dependency between two or more nonkey attributes.
C. A relation that is in first normal form.
D. A relation that is in second normal form.

Correct Answer: B. A functional dependency between two or more nonkey attributes.

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