Data-warehouse T/F Midterm questions

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57. Generalization is a top-down process.

Answer: FALSE

71. The relationship between a weak entity type and its owner is an identifying relationship.

Answer: TRUE

85. It is desirable that no two attributes across all entity types have the same name.

Answer: TRUE

60. CASE tools can model more complex data relationships such as ternary relationships.,

Answer: FALSE

49. File processing systems have been replaced by database systems in most critical business applications today.

Answer: : TRUE

50. Unplanned duplicate data files are the rule rather than the exception in file processing systems.

Answer: : TRUE

100. The relational data model is no longer popular in the 21st century.

Answer: FALSE

104. In two-tier database architectures little functionality needs to be programmed into the client application.,

Answer: FALSE

47. A composite key consists of only one attribute.

Answer: FALSE

48. Databases were developed as the first application of computers to data processing.

Answer: FALSE

49. A foreign key is a primary key of a relation that also is a primary key in another relation.

Answer: FALSE

49. A subtype is a generic entity that has a relationship with one or more entities at a lower level.

Answer: FALSE

49. The intent of a business rule is to break down business structure.

Answer: FALSE

51. A member of a subtype does NOT necessarily have to be a member of the supertype.

Answer: FALSE

51. An enterprise key is a foreign key whose value is unique across all relations.

Answer: FALSE

51. Organizations that utilize the file processing approach spend only 20 percent of development time on maintenance.

Answer: FALSE

51. When systems are automatically generated and maintained quality is diminished.,

Answer: FALSE

52. A business rule is a statement of how a policy is enforced or conducted.

Answer: FALSE

52. Supertype/subtype relationships should be used when the instances of a subtype participate in no relationships which are unique to that subtype.

Answer: FALSE

53. There can be multivalued attributes in a relation.

Answer: FALSE

53. With the traditional file processing approach each application shares data files, thus enabling much data sharing.,

Answer: FALSE

54. The following figure is an example of total specialization.

Answer: FALSE

55. Business rules are formulated from a collection of business ramblings.

Answer: FALSE

55. Unlike columns the rows of a relation may not be interchanged and must be stored in one sequence.,

Answer: FALSE

56. A well-structured database establishes the entities between relationships in order to derive the desired information.

Answer: FALSE

56. The total specialization rule states that an entity instance of a supertype is allowed not to belong to any subtype.

Answer: FALSE

57. An example of a term would be the following sentence: "A student registers for a course."

Answer: FALSE

58. A synonym is an attribute that may have more than one meaning.

Answer: FALSE

58. The data that you are interested in capturing about an entity is called an instance.

Answer: FALSE

59. When the total specialization rule is set for a supertype/subtype relationship one could roughly compare the supertype to an abstract class in object-oriented programming.,

Answer: FALSE

60. The disjoint rule specifies that if an entity instance of the supertype is a member of one subtype it MUST simultaneously be a member of another subtype.,

Answer: FALSE

62. The following figure is an example of the overlap rule.

Answer: FALSE

62. When transforming a weak entity one should create one relation with both the attributes of the strong entity and the attributes of the weak entity.,

Answer: FALSE

63. A user view is how the user sees the data when it is produced.

Answer: FALSE

63. The primary key of the many side migrates to the one side when transforming a one-to-many relationship.

Answer: FALSE

63. When subtypes are overlapping an additional field must be added to the supertype to act as a discriminator.,

Answer: FALSE

64. Most systems developers believe that data modeling is the least important part of the systems development process.

Answer: FALSE

64. When transforming a one-to-one relationship a new relation is always created.,

Answer: FALSE

66. An identifier assigned to an associative entity is also called a cross-relation key.

Answer: FALSE

67. A constraint is a rule in a database system that can be violated by users.

Answer: FALSE

67. The purpose of data modeling is to document business rules about processes.

Answer: FALSE

68. In an E-R diagram strong entities are represented by double-walled rectangles.,

Answer: FALSE

68. Reduced program maintenance is an advantage of file processing systems.

Answer: FALSE

68. Subtypes at the lowest level of a hierarchy do not inherit attributes from their ancestors.

Answer: FALSE

68. When transforming a unary many-to-many relationship to relations a recursive foreign key is used.,

Answer: FALSE

69. In the figure shown below a rental unit can be both a house and an apartment.,

Answer: FALSE

69. The relational data model does at this time, directly support subtype/supertype relationships.,

Answer: FALSE

70. Data integrity consists of powerful operations to manipulate data stored in relations.

Answer: FALSE

70. Data names do not have to be unique.

Answer: FALSE

70. The term legacy system refers to a newly installed database management system.

Answer: FALSE

72. An entity type on which a strong entity is dependent is called a covariant entity.

Answer: FALSE

72. In the figure shown below a rental unit can be both an apartment and a house but must be at least one.,

Answer: FALSE

72. Organizational commitment to a database project is not necessary for its success.

Answer: FALSE

72. The entity integrity rule states that a primary key attribute can be null.

Answer: FALSE

73. In the relational data model associations between tables are defined through the use of primary keys.,

Answer: FALSE

73. Regardless of the business situation a member of the supertype is always a member of more than one subtype.,

Answer: FALSE

73. Repositories are always used in file processing systems.

Answer: FALSE

74. The name used for an entity type should never be the same in other E-R diagrams on which the entity appears.

Answer: FALSE

75. Personal databases are designed to support a small group of individuals working together on a project.

Answer: FALSE

75. Some examples of attributes are: eye_color

Answer: FALSE

76. A simple attribute can be broken down into smaller pieces.

Answer: FALSE

76. Database development begins with the design of the database.

Answer: FALSE

76. The truncate table statement in SQL creates a new table.

Answer: FALSE

77. An enterprise data model describes the scope of data for only one information system.

Answer: FALSE

78. An anomaly is a type of flaw in the database server.

Answer: FALSE

78. Database development projects are never done in a bottom-up fashion.

Answer: FALSE

78. Packaged data models use an entity type to store union data.

Answer: FALSE

80. Packaged data models cause projects to take more time to build.

Answer: FALSE

80. The steps of the systems development life cycle can only be viewed as a linear process.

Answer: FALSE

81. A co-dependency is a constraint between two attributes or two sets of attributes.

Answer: FALSE

81. A ternary relationship is equivalent to three binary relationships.

Answer: FALSE

82. All projects move from the planning-enterprise modeling step to the planning-conceptual data modeling step of the systems development life cycle.

Answer: FALSE

82. The degree of a relationship is the number of attributes that are associated with it.

Answer: FALSE

83. A relation is in first normal form if it has no more than one multivalued attribute.

Answer: FALSE

84. Creating a data model from a packaged data model requires much more skill than creating one from scratch.

Answer: FALSE

84. The physical structure and storage organization of the database is decided upon during the implementation phase of the systems development life cycle.

Answer: FALSE

84. The relationship among the instances of three entity types is called a unary relationship.

Answer: FALSE

85. A transversal dependency is a functional dependency between two or more nonkey attributes.

Answer: FALSE

85. Database processing programs are coded and tested during the design stage of the systems development life cycle.

Answer: FALSE

86. Adapting a packaged data model from your DBMS vendor makes it difficult for the application to work with other applications from the same vendor.

Answer: FALSE

86. Anomalies do not generally arise out of transitive dependencies.

Answer: FALSE

86. It is not permissible to associate attributes with relationships.

Answer: FALSE

87. A relationship instance is an association between entity instances where each relationship instance includes exactly one entity from each participating entity type.

Answer: FALSE

88. Characteristics of the structure of the database are generally changed during the implementation phase of the database development process.

Answer: FALSE

88. You will never need to map data in current databases to data in a packaged data model.

Answer: FALSE

89. In the figure below the name of the relationship follows the guidelines for naming a relationship.,

Answer: FALSE

90. A cardinality constraint tells what kinds of properties are associated with an entity.

Answer: FALSE

91. The maximum criminality of a relationship is the maximum number of instances of entity B that may be associated with each instance of entity A.

Answer: FALSE

91. Visual programming tools such as Visual Basic have made prototyping more difficult.

Answer: FALSE

92. In the figure shown below a person has to be married.,

Answer: FALSE

92. Systems analysts work directly with both management and users to analyze the business situation and develop detailed project specifications.

Answer: FALSE

94. A customer can order many items and an item can be ordered by many customers is an example of a recursive relationship.,

Answer: FALSE

94. In 1998 ANSI/SPARC published an import document describing the three-schema architecture.,

Answer: FALSE

95. The conceptual schema is always technology specific.

Answer: FALSE

98. The internal schema consists of the physical schema and the enterprise data model.

Answer: FALSE

101. Although personal databases improve productivity one risk is that data cannot be shared with other users.,

Answer: TRUE

102. The most common way to support a group of individuals who work together on a project or group of similar projects is with a two-tier client/server database.

Answer: TRUE

103. Each member of a workgroup accesses data located on a database server.

Answer: TRUE

105. Multitier client/server database applications contain a business logic layer.

Answer: TRUE

106. An enterprise resource planning system integrates all functions of the enterprise.

Answer: TRUE

107. A data warehouse contains summarized and historical information.

Answer: TRUE

108. An extranet uses Internet protocols to establish limited access to company data by the company's customers and suppliers.

Answer: TRUE

46. Data structures include data organized in the form of tables with rows and columns.

Answer: TRUE

46. Information is processed data.

Answer: TRUE

46. The E-R model is used to construct a conceptual model.

Answer: TRUE

47. A business rule is a statement that defines or constrains some aspect of the business.

Answer: TRUE

47. Metadata are data that describe the properties of other data.

Answer: TRUE

48. A primary key is an attribute that uniquely identifies each row in a relation.

Answer: TRUE

48. One of the roles of a database analyst is to identify and understand rules that govern data.

Answer: TRUE

50. An entity instance of a subtype represents the same entity instance of the supertype.

Answer: TRUE

50. Enforcement of business rules can be automated through the use of software tools that can interpret the rules and enforce them.

Answer: TRUE

50. Sample data are useful for developing prototype applications and for testing queries.

Answer: TRUE

52. Many of the disadvantages of file processing systems can also be limitations of databases.

Answer: TRUE

52. One property of a relation is that each attribute within a relation has a unique name.

Answer: TRUE

53. One of the major challenges in data modeling is to recognize and clearly represent entities that are almost the same.

Answer: TRUE

53. While business rules are not redundant a business rule can refer to another business rule.,

Answer: TRUE

54. A business rule should be internally consistent.

Answer: TRUE

54. Development starts from scratch with the traditional file processing approach because new file formats descriptions, and file access logic must be designed for each new program.,

Answer: TRUE

54. The columns of a relation can be interchanged without changing the meaning or use of the relation.

Answer: TRUE

55. A data model is a graphical system used to capture the nature and relationships among data.

Answer: TRUE

55. Specialization is the reverse of generalization.

Answer: TRUE

56. All values that appear in a column of a relation must be taken from the same domain.

Answer: TRUE

56. Data names should always relate to business characteristics.

Answer: TRUE

57. A person is an example of an entity.

Answer: TRUE

57. View integration is the process of merging relations together.

Answer: TRUE

58. A completeness constraint may specify that each entity of the supertype must be a member of some subtype in the relationship.

Answer: TRUE

58. A fact is an association between two or more terms.

Answer: TRUE

59. A good data definition is always accompanied by diagrams such as the entity-relationship diagram.,

Answer: TRUE

59. A relational database establishes the relationships between entities by means of a common field.

Answer: TRUE

59. When two or more attributes describe the same characteristic of an entity they are synonyms.,

Answer: TRUE

60. An entity is a person place, object, event, or concept in the user environment about which the organization wishes to maintain data.,

Answer: TRUE

60. Separation of metadata from application programs that use the data is called data independence.

Answer: TRUE

61. A single occurrence of an entity is called an entity instance.

Answer: TRUE

61. The overlap rule specifies that if an entity instance of the supertype is a member of one subtype it can simultaneously be a member of two (or more. subtypes.,

Answer: TRUE

61. When a regular entity type contains a multivalued attribute two new relations are created.,

Answer: TRUE

62. Redundancy increases the risk of inconsistent data.

Answer: TRUE

63. When choosing an identifier choose one that will not change its value often.,

Answer: TRUE

64. One reason for improved application development productivity with the database approach is that file design and low-level implementation details do not need to be handled by the application programmer.

Answer: TRUE

64. There are three separate discriminators in the following diagram because of the overlap rule.

Answer: TRUE

65. A subtype can become a supertype if the subtype has other subtypes beneath it.

Answer: TRUE

65. Data rather than processes, are the most complex aspects of many modern information systems.,

Answer: TRUE

65. If an identifier is not assigned the default primary key for an associative relation consists of the two primary key attributes from the other two relations.,

Answer: TRUE

65. The data repository assists database administrators in enforcing standards.

Answer: TRUE

66. Data modeling is about documenting rules and policies of an organization that govern data.

Answer: TRUE

66. The failure to implement a strong database administrative function is the most common source of database failures in organizations.

Answer: TRUE

66. The following diagram is an example of a supertype/subtype hierarchy.

Answer: TRUE

67. In a supertype/subtype hierarchy attributes are assigned at the highest logical level that is possible in the hierarchy.,

Answer: TRUE

67. In the figure below each employee has exactly one manager.,

Answer: TRUE

69. Cost and complexity are just two of the disadvantages of database processing.

Answer: TRUE

69. In an E-R diagram an associative entity is represented by a rounded rectangle.,

Answer: TRUE

70. In the figure shown below a rental unit has to be either a house or an apartment.,

Answer: TRUE

71. A modern database management system automates more of the backup and recovery tasks than a file system.

Answer: TRUE

71. In the figure shown below there could be an instance of a rental unit that is neither an apartment nor a house.,

Answer: TRUE

71. The allowable range of values for a given attribute is part of the domain constraint.

Answer: TRUE

73. An entity type name should always be a singular noun.

Answer: TRUE

74. A referential integrity constraint is a rule that maintains consistency among the rows of two relations.

Answer: TRUE

74. Entity clustering is a methodology for grouping one or more entity types and associated relationships into a single abstract entity type.

Answer: TRUE

74. The user interface includes languages menus, and other facilities by which users interact with various system components.,

Answer: TRUE

75. A cascading delete removes all records in other tables associated with the record to be deleted.

Answer: TRUE

75. An entity cluster should focus on some area of interest to some community of users developers or managers.,

Answer: TRUE

76. An entity cluster can have a relationship with another entity cluster much the same way that an entity can have a relationship with another entity.

Answer: TRUE

77. A well-structured relation contains minimal redundancy and allows users to manipulate the relation without errors or inconsistencies.

Answer: TRUE

77. An attribute whose values can be calculated from related attribute values is called a derived attribute.

Answer: TRUE

77. Packaged data models are meant to be customized.

Answer: TRUE

78. A multivalued attribute may take on more than one value for a particular entity instance.

Answer: TRUE

79. A universal data model is a generic or template data model that can be reused as a starting point for a data modeling project.

Answer: TRUE

79. Relationships represent action being taken using a verb phrase.

Answer: TRUE

79. The systems development life cycle is the traditional methodology used to develop maintain, and replace information systems.,

Answer: TRUE

79. When normalizing the goal is to decompose relations with anomalies to produce smaller, well-structured relations.,

Answer: TRUE

80. A relation in fifth normal form may not contain any anomalies.

Answer: TRUE

80. Participation in a relationship may be optional or mandatory.

Answer: TRUE

81. Enterprise modeling sets the range and general contents of organizational databases.

Answer: TRUE

81. Packaged data models can be developed using proven components.

Answer: TRUE

82. A candidate key is an attribute or combination of attributes, that uniquely identifies a row in a relation.,

Answer: TRUE

83. Packaged data models are as flexible as possible because all supertype/subtype relationships allow the total specialization and overlap rules.,

Answer: TRUE

83. The relationship between the instances of two entity types is called a binary relationship.

Answer: TRUE

83. The repository is populated during the analysis phase of the systems development life cycle.

Answer: TRUE

84. A partial functional dependency is a functional dependency in which one or more nonkey attributes are functionally dependent on part (but not all. of the primary key.

Answer: TRUE

85. It is easier to share information across organizations if companies in the same industry use the same universal data model as the basis for their organizational databases.

Answer: TRUE

86. Data from prior systems is converted to the new system during the implementation phase of the systems development life cycle.

Answer: TRUE

87. Because a purchased data model is extensive you begin by identifying the parts of the data model that apply to your data modeling situation.,

Answer: TRUE

87. Database maintenance is typically the longest step of the database development process.

Answer: TRUE

88. One reason to use an associative entity is if the associative entity has one or more attributes in addition to the identifier.

Answer: TRUE

89. Mapping existing data to new data in a packaged data model is useful for developing migration plans.

Answer: TRUE

89. Prototyping is a type of rapid application development.

Answer: TRUE

90. In prototyping implementation and maintenance activities are repeated as necessary until the product is correct.,

Answer: TRUE

90. It is easy to miss the opportunity to visualize future requirements shown in the full data model when using a packaged data model.

Answer: TRUE

91. The most important challenge of customizing a purchased data model is determining the business rules that will be established through the data model.

Answer: TRUE

93. Database architects establish standards for data in business units.

Answer: TRUE

93. For the relationship represented in the figure below a department can have more than one employee.,

Answer: TRUE

95. A time stamp is a time value that is associated with a data value.

Answer: TRUE

96. The external schema contains a subset of the conceptual schema relevant to a particular group of users.

Answer: TRUE

97. A physical schema contains the specifications for how data from a conceptual schema are stored in a computer's secondary memory.

Answer: TRUE

99. E. F. Codd developed the relational data model during the 1970s.

Answer: TRUE

61. Data redundancy is used to establish relationships between data but is never used to improve database performance.

Answer: FALSE

82. Data models of an existing database are harder for data modelers to read.

Answer: FALSE


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