BCIS 4000 CHAPTER 6 COPY
11. A dependency of one nonprime attribute on another nonprime attribute is a partial dependency. a. True b. False
False
13. Dependencies that are based on only a part of a composite primary key are called transitive dependencies. a. True b. False
False
18. A determinant is any attribute whose value determines other values within a column. a. True b. False
False
19. Data stored at their highest level of granularity are said to be atomic data. a. True b. False
False
2. Normalization is a process that is used for changing attributes to entities. a. True b. False
False
20. Atomic attributes are attributes that can be further subdivided. a. True b. False
False
21. A table is in BCNF if every determinant in the table is a foreign key. a. True b. False
False
24. The combination of normalization and ER modeling yields a useful ERD, whose entities can be translated into appropriate relationship structures. a. True b. False
False
25. A good relational DBMS excels at managing denormalized relations. a. True b. False
False
27. Normalization purity is often easy to sustain in the modern database environment. a. True b. False
False
29. Attributes should clearly define participation, connectivity, and document cardinality. a. True b. False
False
5. Normalization is a very important database design ingredient, and the highest level is always the most desirable. a. True b. False
False
6. Reporting anomalies in a table can cause a multitude of problems for managers and can be fixed through application programming. a. True b. False
False
1. Normalization works through a series of stages called normal forms. a. True b. False
True
10. Repeating groups must be eliminated by ensuring that each row defines a single entity. a. True b. False
True
12. Dependency diagrams are very helpful in getting a bird's-eye view of all the relationships among a table's attributes. a. True b. False
True
14. All relational tables satisfy the 1NF requirements. a. True b. False
True
15. In the context of partial dependencies, data redundancies occur because every row entry requires duplication of data. a. True b. False
True
16. Since a partial dependency can exist only if a table's primary key is composed of several attributes, if a table in 1NF has a single-attribute primary key, then the table is automatically in 2NF. a. True b. False
True
17. It is possible for a table in 2NF to exhibit transitive dependency, where the primary key may rely on one or more nonprime attributes to functionally determine other nonprime attributes. a. True b. False
True
22. A table is in fourth normal form if it is in third normal form and has no independent multivalued dependencies. a. True b. False
True
23. Normalization represents a micro view of the entities within the ERD. a. True b. False
True
26. The advantage of higher processing speed must be carefully weighed against the disadvantage of data anomalies. a. True b. False
True
28. Unnormalized database tables often lead to various data redundancy disasters in production databases. a. True b. False
True
3. In order to meet performance requirements, portions of the database design may need to be occasionally denormalized. a. True b. False
True
4. Denormalization produces a lower normal form. a. True b. False
True
7. Data redundancy produces data anomalies. a. True b. False
True
8. The objective of normalization is to ensure that each table conforms to the concept of well-formed relations. a. True b. False
True
9. Relational models view data as part of a table or collection of tables in which all key values must be identified. a. True b. False
True
32. From a structural point of view, 2NF is better than _____. a. 1NF b. 3NF c. 4NF d. BCNF
a
36. Attribute A _____ attribute B if all of the rows in the table that agree in value for attribute A also agree in value for attribute B. a. determines b. derives from c. controls d. owns
a
39. A table that has all key attributes defined, has no repeating groups, and all its attributes are dependent on the primary key is said to be in _____. a. 1NF b. 2NF c. 3NF d. 4NF
a
48. Improving _____ leads to more flexible queries. a. atomicity b. normalization c. denormalization d. derived attribute
a
52. From a system functionality point of view, _____ attribute values can be calculated when they are needed to write reports or invoices. a. derived b. atomic c. granular d. historical
a
56. A table where every determinant is a candidate key is said to be in _____. a. BCNF b. 2NF c. 1NF d. 4NF
a
59. In a _____ situation, one key determines multiple values of two other attributes and those attributes are independent of each other. a. multivalued dependency b. transitive dependency c. partial dependency d. functional dependency
a
62. When designing a database, you should _____. a. make sure that entities are in normal form before table structures are created b. create table structures then normalize the database c. only normalize the database when performance problems occur d. consider more important issues such as performance before normalizing
a
30. Normalization works through a series of stages called normal forms. For most purposes in business database design, _____ stages are as high as you need to go in . a. two b. three c. four d. five
b
31. From a structural point of view, 3NF is better than _____. a. 4NF b. 2NF c. 5NF d. 6NF
b
34. A table that displays data redundancies yields _____. a. consistencies b. anomalies c. fewer attributes d. more entities
b
44. In a(n) _____ diagram, the arrows above the attributes indicate all desirable dependencies. a. Chen b. dependency c. functionality d. ER
b
45. Dependencies based on only a part of a composite primary key are known as _____ dependencies. a. primary b. partial c. incomplete d. composite
b
49. An atomic attribute _____. a. cannot exist in a relational table b. cannot be further subdivided c. displays multiplicity d. is always chosen to be a foreign key
b
51. Granularity refers to _____. a. the size of a table b. the level of detail represented by the values in a table's row c. the number of attributes represented in a table d. the number of rows in a table
b
53. In a real-world environment, we must strike a balance between design integrity and _____. a. robustness b. flexibility c. uniqueness d. ease of use
b
57. BCNF can be violated only if the table contains more than one _____ key. a. primary b. candidate c. foreign d. secondary
b
58. When a table contains only one candidate key, _____ are considered to be equivalent. a. the 1NF and the 2NF b. the 3NF and the BCNF c. the 4NF and the 3NF d. the BCNF and the DKNF
b
65. Data warehouse routinely uses _____ structures in its complex, multilevel, multisource data environment. a. 1NF b. 2NF c. 3NF d. 4NF
b
66. _____ databases reflect the ever-growing demand for greater scope and depth in the data on which decision support systems increasingly rely. a. Normalized b. Data warehouse c. Temporary d. Report
b
33. An attribute that is part of a key is known as a(n) _____ attribute. a. important b. nonprime c. prime d. entity
c
40. A(n) _____ exists when there are functional dependencies such that XY is functionally dependent on WZ, X is functionally dependent on W, and XY is the primary key. a. atomic attribute b. repeating group c. partial dependency d. transitive dependency
c
42. A _____ derives its name from the fact that a collection of multiple entries of the same type can exist for any single key attribute occurrence. a. partial dependency b. transitive dependency c. repeating group d. primary key
c
47. A table that is in 2NF and contains no transitive dependencies is said to be in _____. a. 1NF b. 2NF c. 3NF d. 4NF
c
54. For most business transactional databases, we should normalize relations into _____. a. 1NF b. 2NF c. 3NF d. 6NF
c
55. To generate a surrogate key, Microsoft Access uses a(n) _____ data type. a. character b. sequence c. AutoNumber d. identity
c
61. A table is in 4NF if it is in 3NF, and _____. a. all attributes must be dependent on the primary key and must be dependent on each other b. all attributes are unrelated c. it has no multivalued dependencies d. no column contains the same values
c
64. The conflicts between design efficiency, information requirements, and performance are often resolved through _____. a. compromises that include normalization b. conversion from 2NF to 3NF c. compromises that include denormalization d. conversion from 3NF to 4NF
c
35. Data redundancy produces _____. a. slower lookups b. robust design c. efficient storage use d. data integrity problems
d
37. Some very specialized applications may require normalization beyond the _____. a. 1NF b. 2NF c. 3NF d. 4NF
d
38. Of the following normal forms, _____ is mostly of theoretical interest. a. 1NF b. 3NF c. BCNF d. DKNF
d
41. A(n) _____ exists when there are functional dependencies such that Y is functionally dependent on X, Z is functionally dependent on Y, and X is the primary key. a. partial dependency b. repeating group c. atomic attribute d. transitive dependency
d
43. A relational table must not contain a(n) _____. a. entity b. attribute c. relationship d. repeating group
d
50. The most likely data type for a surrogate key is _____. a. character b. date c. logical d. numeric
d
60. A table where all attributes are dependent on the primary key but are independent of each other, and no row contains two or more multivalued facts about an entity is said to be in _____. a. 1NF b. 2NF c. 3NF d. 4NF
d
63. An example of denormalization is using a _____ denormalized table to hold report data. This is required when creating a tabular report in which the columns represent data that are stored in the table as rows. a. transitive b. 3NF c. component d. temporary
d
46. If a table has multiple candidate keys and one of those candidate keys is a composite key, the table can have _____ based on this composite candidate key even when the primary key chosen is a single attribute. a. Boyce-Codd normal forms b. redundancies c. time-variances d. partial dependencies
d partial dependencies
