CS 682 FINAL without 6

121. Which of the following is a criteria for making a good data model? A) A good data model is simple. B) A good data model is essentially nonredundant. C) A good data model should be flexible and adaptable to future needs. D) Each data attribute should describe at most one entity. E) All of these.

All of these.

108. A relationship where many instances of one entity can be associated with many instances of another entity is known as: A) ternary B) many-to-many C) nonspecific D) B and C E) none of these

B and C

114. Which of the following statements is false?: A) Data models help analysts to quickly identify business vocabulary more completely than process models. B) Data models are almost always built more quickly than process models. C) Data models for existing and proposed systems are far more similar than process models for existing and proposed systems. D) Data modelers frequently get hung up on unnecessary details associated with the data. E) None of these.

Data modelers frequently get hung up on unnecessary details associated with the data.

11. A compound attribute is an attribute that will be expanded into a separate entity.

False

15. The domain value for an attribute is the value that will be recorded if not specified by the user.

False

17. A key is an attribute or group of attributes that assumes a unique value for each entity instance. It is sometimes called the domain of the attribute.

False

2. Data modeling is a technique for organizing and documenting a system's logical and physical models.

False

20. A candidate key must be a single attribute.

False

27. A subsetting criteria is a domain of attributes whose values are limitless to allow for a variety of subsets to be constructed from a database.

False

29. A relationship may represent an event that links the entities or merely a physical affinity that exists between the entities.

False

30. All data model relationships are unidirectional.

False

32. Conceptually cardinality defines the minimum and maximum attributes that can be added to an entity.

False

34. The domain of a relationship is the number of entities that participate in the relationship.

False

42. A foreign key in the parent entity always matches the primary key in the child entity.

False

44. Nonidentifying relationships are those in which each of the participating entities has dependent primary keys.

False

48. A many-to-many relationship is one in which many entities are associated with other attributes of a different entity.

False

50. Generalization is a technique wherein the domains common to several types of attributes are grouped into their own entity, called an associate entity.

False

52. An entity supertype is an entity whose instances inherit some common attributes from an entity subtype and then add other attributes that are unique to an instance of the supertype.

False

54. An enterprise data model typically identifies and defines only the most complex entities used by the enterprise.

False

58. The requirements analysis results in a physical data model that is developed in stages as follows: (1) normalized data model; (2) key-based data model; (3) fully attributed data model; and (4) the context data model.

False

75. If use-case narratives have been written during the requirements analysis phase, analysts can scan them for verbs to discover data attributes and entities.

False

8. An entity existence is a single occurrence of an entity.

False

80. In a good data mode, each data attribute describes at most one entity.

False

82. A good data model is inflexible because it is an accurate representation of the business data requirements.

False

83. Data analysis is a process that prepares a logical model for implementation as a redundant, explicit, and finite database through a technique called generalization.

False

87. An entity is in third normal form (3NF) if it is already in 2NF and if the values of all nonprimary key attributes are dependent on the full primary key - not just part of it.

False

88. An entity is in first normal form (1NF) if the values of its nonprimary key attributes are not dependent on any other nonprimary key attributes.

False

89. One form of 3NF makes sure that transitive dependencies exist in each entity.

False

91. A data-to-location CRUD matrix is a table in which garbage values that fall outside the domain of an attribute are identified and used for data verification.

False

93. A generalization hierarchy can be at most two levels deep.

False

120. Which of the following is NOT a guideline for creating a business coding scheme? A) Codes should be expandable to accommodate growth. B) The full code must result in redundant values for entities. C) Codes should be large enough to describe distinguishing characteristics, but small enough to be interpreted by a person without a computer. D) Codes should be convenient. E) All of these

The full code must result in redundant values for entities.

74. Hierarchical codes provide a top-down interpretation for an entity instance by factoring an item into its group, subgroup and so forth.

True

77. Many organizations have naming standards and approved abbreviations for data attributes.

True

78. A good data model is simple.

True

79. A good data model is essentially nonredundant.

True

81. A good data model should be flexible and adaptable to future needs.

True

84. An entity is in first normal form (1NF) if there are no attributes that can have more than one value for a single instance of the entity.

True

85. An entity is in second normal form (2NF) if it is already in 1NF and if the values of all nonprimary key attributes are dependent on the full primary key - not just part of it.

True

9. An attribute is a descriptive property or characteristic of an entity.

True

90. A data-to-location CRUD matrix is a table in which the rows indicate entities (and possible attributes); the columns indicate locations; and the cells (the intersection of the rows and columns) document level of access where C=create; R=read; U=update; and D=delete or deactivate.

True

92. Many nonspecific relationships can be resolved into two one-to-many relationships using an associative entity.

True

111. The data model for a single information system is usually called: A) the enterprise data model B) the logical data model C) the physical data model D) the application data model E) none of these

the application data model

72. In significant position codes, each digit or group of digits describes a measurable or identifiable characteristic of the entity instance.

True

73. Significant position codes are frequently used to code inventory items.

True

1. Data modeling is a technique for defining business requirements for a database.

True

10. A compound attribute is one that actually consists of other attributes that are logically grouped together.

True

12. The data type of an attribute defines what type of data can be stored in that attribute.

True

13. Example data types include: numbers, text, memo, date, time, yes/no, Boolean, value set, or image.

True

14. The domain of an attribute defines what values an attribute can legitimately take on.

True

18. A concatenated key is a group of attributes that uniquely identifies an instance of an entity.

True

19. A concatenated key is also known as a composite key or a compound key.

True

21. A candidate key may be a single attribute or a concatenated key.

True

22. A primary key is that candidate key that will most commonly be used to uniquely identify a single entity instance.

True

23. An example of domain would be an attribute called grade where the values could only be A, B, C, D, E, or F.

True

24. An alternate key is also known as a secondary key.

True

25. A subsetting criteria is an attribute or concatenated attribute whose finite values divide all entity instances into useful subsets.

True

28. A relationship is a natural business association that exists between one or more entities.

True

3. Data modeling is sometimes called database modeling because a data model is eventually implemented as a database.

True

31. Because all relationships are bi-directional in an entity relationship diagram, cardinality must be defined in both directions for every relationship.

True

33. The degree of a relationship is the number of entities that participate in the relationship.

True

35. A recursive relationship is when only one entity participates in the relationship.

True

37. A recursive relationship identifies a relationship that may exist between different instances of the same entity.

True

38. A ternary relationship is a relationship among three entities.

True

39. The relationship between a student entity and a curriculum entity would be classified as recursive.

True

4. An entity is something about which the business needs to store data.

True

40. In a one-to-many relationship, the parent is the entity on the "one" side.

True

41. A foreign key in a child entity always matches the primary key in the parent entity.

True

43. Nonidentifying relationships are those in which each of the participating entities has its own independent primary key. That is, none of the primary key attributes is shared.

True

45. Identifying relationships are those in which the parent entity contributes its primary key to become part of the primary key of the child entity.

True

47. A non-specific relationship is one in which many instances of one entity are associated with many instances of another entity.

True

49. Generalization is a technique wherein the attributes that are common to several types of an entity are grouped into their own entity, called a supertype.

True

5. An entity is a class of persons, places, objects, events or concepts about which we need to capture and store data.

True

51. An entity subtype is an entity whose instances inherit some common attributes from an entity supertype and then add other attributes that are unique to an instance of the subtype.

True

53. An enterprise data model typically identifies only the most fundamental of entities of the enterprise.

True

55. The data model for a single information system is usually called an application data model.

True

57. The requirements analysis results in a logical data model that is developed in stages as follows: (1) context data model; (2) key-based data model; (3) fully attributed data model; and (4) the normalized data model.

True

59. During systems design, the logical data model will be transformed into a physical data model.

True

7. An entity instance is a single occurrence of an entity.

True

70. Serial codes assign sequentially generated numbers to entity instances.

True

71. Alphabetic codes use finite combinations of letters (and possibly numbers) to describe entity instances.

True

119. A code that provides a top-down interpretation for an entity instance is known as: A) a serial code B) a structured code C) a significant position code D) a hierarchical code E) none of these

a hierarchical code

117. A code that assigns sequentially generated numbers to entity instances is known as: A) a serial code B) a sequential code C) an alphabetic code D) a significant position code E) none of these

a serial code

94. Which of the following is a category of entities? A) person B) place C) object D) concept E) all of these

all of these

101. If an employee entity had both an EmployeeID attribute and a Social Security Number attribute, the one that was not used as the primary key would be called a(n): A) entity key B) concatenated key C) alternate key D) candidate key E) all of these

alternate key

95. A descriptive property or characteristic of an entity is: A) a domain B) an attribute C) an entity instance D) an entity existence E) none of these

an attribute

105. A ternary relationship is: A) recursive B) reflexive C) between three entities D) is not possible in data modeling E) none of these

between three entities

118. A code that uses blocks of numbers that are divided into groups that have some business meaning is known as a: A) serial code B) hierarchical code C) significant position code D) block code E) none of these

block code

103. What defines the minimum and maximum number of occurrences of one entity that may be related to a single occurrence of the other entity? A) domain B) concatenation C) associative entity D) cardinality E) none of these

cardinality

113. During requirements analysis, what order of model development is used to arrive at the logical data model? A) context data model; fully attributed data model; key-based data model; normalized data model B) normalized data model; context data model; fully attributed data model; key-based data model C) normalized data model; key-based data model; fully attributed data model; context data model D) context data model; key-based data model; fully attributed data model; normalized data model E) none of these

context data model; key-based data model; fully attributed data model; normalized data model

98. The value that is recorded in an attribute if a user does not specify one is known as the: A) domain B) key C) default value D) data type E) none of these

default value

97. What defines what values an attribute can legitimately take on? A) realm B) entity C) relationship D) domain E) none of these

domain

109. A technique wherein attributes that are common to several types of an entity are grouped into their own entity called a supertype is called: A) normalization B) generalization C) concatenation D) compound data type E) none of these

generalization

107. When a parent entity contributes its primary key to become part of the primary key of the child entity, the relationship is known as: A) primary B) associative C) nonidentifying D) identifying E) none of these

identifying

102. An attribute or concatenated attribute whose values divide all entity instances into useful subsets is known as: A) primary criteria B) secondary criteria C) alternate criteria D) subsetting criteria E) none of these

subsetting criteria

110. An entity whose instances store attributes that are common to one or more entities is a(n): A) supertype B) subtypes C) compound type D) default type E) none of these

supertype

100. Any candidate key that is not selected to become the primary key is called: A) the entity key B) the concatenated key C) the subsetting key D) the domain key E) the alternate key

the alternate key

99. An attribute or group of attributes that assumes a unique value for each entity instance is a: A) domain B) key C) default value D) data type E) none of these

key

115. A true entity: A) must have only one instance B) must have many possible instances C) must have a recursive relationship D) must have the same cardinality and degree E) all of these

must have many possible instances

112. The problem analysis phase model that includes only entities and relationships but no attributes is known as: A) the enterprise data model B) the application data model C) the context data model D) does not exist, all data models must have attributes E) none of these

the context data model

104. The number of entities that can participate in a relationship is known as: A) the domain of the relationship B) the cardinality of the relationship C) the degree of the relationship D) the association of the relationship E) none of these

the degree of the relationship