Database Quiz

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1. Set of permitted values of each attributes are called

A . Row
B. Column
C. Domain
D. Schema

2. Which of the following statements is not true

A. All primary keys are super keys
B. A candidate key can have a proper subset which is a super key
C. All super keys are not candidate keys
D. A candidate key may not be a super key

3. Entity integrity means that

A. A primary key cannot be null.
B. A foreign key cannot be null.
C. A primary key can be partially null.
D. A foreign key can be partially null.

4. The target of a foreign key should be

A. Foreign key in another table
B. Primary key in another table
C. Super key in another table
D. Primary key in the same table

5. Which of the following can not be the mapping cardinality of a foreign key

A. One- one
B. Many - many
C. Many- one

6. SQL is a

A. Host language
B. Application language
C. Data manipulation language

7. In the following ER diagram,


mapping cardinality of the relation is many one, which means
one manager can manage

A. zero or more departments
B. one or more departments
C. more than one department
D. exactly one department

8. Entity, that can not be uniquely identified by its own attributes , is called

A . Composite entity
B. Strong entity
C. Weak entity
D. Simple entity

In schema S = {A,B,C,D,E,F,G,H}, suppose the following hold for S.
AB --> CD
E --> F
F --> G

9. Which of the following holds true with respect to the above schema

A. CD --> AB
B. AB --> ACD
C. A --> CD
D. AB --> C

10. Which of the following does not hold true.

A. E --> G
B. ABE -->CDE
C. AB --> ABH
D. AB --> null set







Answers

1. A
2. B
3. A
4. B
5. B
6. C
7. A
8. C
9. D
10. C