Logical Database Design problems
- 1. A transitive dependency is which of the following?
Options- 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. Discuss
Correct Answer: A functional dependency between two or more nonkey attributes.
- 2. When mapping a regular entity into a relation which of the following is true?
Options- A. One relation is created.
- B. Two relations are created.
- C. Three relations are created.
- D. Four relations are created. Discuss
Correct Answer: One relation is created.
- 3. When mapping a ternary relationship with an associative entity into a relation which of the following is true?
Options- A. One relation is created.
- B. Two relations are created.
- C. Three relations are created.
- D. Four relations are created. Discuss
Correct Answer: Four relations are created.
- 4. When mapping a supertype/subtype relationship which of the following is true?
Options- A. The supertype primary key is assigned to each subtype.
- B. The subtype primary key is assigned to each supertype.
- C. There is no link between the supertype/subtype entities.
- D. There is no primary key/foreign key relationship between a supertype/subtype. Discuss
Correct Answer: The supertype primary key is assigned to each subtype.
- 5. When mapping a multivalued attribute into a relation which of the following is true?
Options- A. One relation is created.
- B. Two relations are created.
- C. Three relations are created.
- D. Four relations are created. Discuss
Correct Answer: Two relations are created.
- 6. Weak entities do not get mapped into a relation.
Options- A. True
- B. False Discuss
Correct Answer: False
- 7. In a 1:M relationship, the primary key on the one side migrates to the many side to become the foreign key on the many side.
Options- A. True
- B. False Discuss
Correct Answer: True
- 8. A primary key may be null.
Options- A. True
- B. False Discuss
Correct Answer: False
- 9. The primary key of the new relation in a many-to-many relationship is a composite key comprised of the primary keys of each of the binary entities.
Options- A. True
- B. False Discuss
Correct Answer: True
- 10. An enterprise key is a primary key whose value is unique for a given relation.
Options- A. True
- B. False Discuss
Correct Answer: False
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