Data-warehouse T/F Midterm questions
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 File processing systems have been replaced by database systems in most critical business applications today.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
