IST 331 Chapter 5: Logical Database Design and the Relational Model

IST 331Chapter 5: Logical Database Design and the Relational Model

Spring 2002

V. Matos

1. In ___ normal form, any multivalued attributes have been removed.

a)[VM1]first

b)second

c)fourth

d)fifth

2. In ____ normal form, any transitive dependencies have been removed.[VM2]

a)first

b)second

c)third

d)fourth

3. Another name for a synonym is a(n)[VM3]

a)alias.

b)homonym.

c)constraint.

d)enterprise key.

4. A(n) ____ is an attribute that uniquely identifies each row in a relation.[VM4]

a)composite key

b)foreign key

c)identifier

d)primary key

5. A(n) ____ is an attribute in a relation that serves as a primary key of another relation in the same database.[VM5]

a)composite key

b)foreign key

c)identifier

d)primary key

6. Two common ways of expressing a conceptual schema are[VM6]

a)text (narrative) and physical.

b)physical and mathematical.

c)mathematical and graphical.

d)graphical and text (narrative).

7. The ____ guarantees that every primary key attribute is not null.[VM7]

a)entity integrity rule

b)referential integrity constraint

c)action assertion

d)composite attribute

8. The ____ states that a foreign key must either match a primary key value in another relation or it must be null.[VM8]

a)entity integrity rule

b)referential integrity constraint

c)action assertion

d)composite attribute

9. A(n) ____ contains minimal data redundancy.[VM9]

a)anomaly

b)action assertion

c)well-structured relation

d)associative entity

10. A(n) ____ is a constraint between two attributes.[VM10]

a)determinant

b)action assertion

c)candidate

d)functional dependency

11. This is similar to an object-oriented database’s object identifier.

a)enterprise key

b)primary key

c)foreign key

d)secondary key

12. Which is NOT a problem that may arise in view integration or merging?

a)Synonyms

b)Transitive dependencies

c)Homonyms

d)functional dependency

13. A(n) ____ corresponds to a column in the relation.

a)constraint

b)key

c)attribute

d)reference

14. ____ entities are entities that cannot exist except with an identifying relationship with a regular entity type.

a)Composite

b)Regular

c)Associative

d)Weak

15. ____ entities are also called gerunds.

a)Composite

b)Regular

c)Associative

d)Weak

16. The hierarchical data model is the most commonly used model in contemporary database applications.

a)TRUE

b)FALSE

17. The relational model was first introduced in the 1980s by E.F. Codd.

a)TRUE

b)FALSE

18. Another name for a relation is a table.

a)TRUE

b)FALSE

19. EMPLOYEE1(Emp_ID, Name, Dept, Salary) describes four tables.

a)TRUE

b)FALSE

20. A composite key is an attribute in one table that acts as a primary key in another table.

a)TRUE

b)FALSE

21. The entity integrity rule states that no primary key attribute (or component) may be null.

a)TRUE

b)FALSE

22. Redundancies in a table may cause anomalies.

a)TRUE

b)FALSE

23. A weak entity type can exist independent of its relationship with other entity types.

a)TRUE

b)FALSE

24. The procedure for representing relationships depends solely on the cardinalities of the relationships.

a)TRUE

b)FALSE

25. In 1:M relationships, the entity on the one-side of the relationship becomes a foreign key in the table of the many-side of the relationship.

a)TRUE

b)FALSE

26. A recursive foreign key is used in a unary relationship.

a)TRUE

b)FALSE

27. Normalization is the process of decomposing relations to produce smaller, well-structured relations.

a)TRUE

b)FALSE

28. A determinant is a constraint between two attributes or sets of attributes.

a)TRUE

b)FALSE

29. A determinant is an attribute or combination of attributes that uniquely identifies a row in a relation.

a)TRUE

b)FALSE

30. An attribute having more than one meaning is called a synonym.

a)TRUE

b)FALSE

31. Draw a Relational Database Representation for the following Entity-Relationship diagram.

32. The following STUDENT-ADVISOR table is part of the University database.

Student-Advisor

(1) Answer the following questions.

(2) (If needed!) Draw a 3NF database representation for the Student-Advisor table.

IST331-Exam2 Page 1

[VM1]first

CORRECT. All multivalued (or repeating groups) have been removed so there is a single value at the intersection of each row and column in a table.

[VM2]third

CORRECT. In the third normal form, all functional dependencies between nonkey attributes have been removed.

[VM3]alias.

CORRECT. Another name for a synonym is an alias, which is an alternative name used for an attribute.

[VM4]primary key

CORRECT. A primary key uniquely identifies each row.

[VM5]foreign key

CORRECT. A foreign key is an attribute that is a primary key in another relation.

[VM6]graphical and text (narrative).

CORRECT. Text and graphical are commonly used. Text is simpler; however graphical better expresses constraints.

[VM7]entity integrity rule

CORRECT. A null is an absence of a value.

[VM8]referential integrity constraint

CORRECT. The referential integrity constraint is used to maintain consistency among the rows of two relations.

[VM9]well-structured relation

CORRECT. A well-structured relation contains minimal redundancy. Redundancies in a table may lead to errors or inconsistencies (anomalies).

[VM10]functional dependency

CORRECT. Function dependency is a constraint between two attributes and is usually represented by an arrow.