Chapter 2: Data Models

24 July 2022
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A data model is usually graphical. a. True b. False
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ANSWER: True
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An implementation-ready data model needn't necessarily contain enforceable rules to guarantee the integrity of the data. a. True b. False
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ANSWER: False
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An implementation-ready data model should contain a description of the data structure that will store the end-user data. a. True b. False
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ANSWER: True
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Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain. a. True b. False
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ANSWER: True
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Even when a good database blueprint is available, an applications programmer's view of the data should match that of the manager and the end user. a. True b. False
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ANSWER: False
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In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored. a. True b. False
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ANSWER: True
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Database designers determine the data and information that yield the required understanding of the entire business. a. True b. False
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ANSWER: False
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Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories. a. True b. False
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ANSWER: False
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Business rules must be rendered in writing. a. True b. False
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ANSWER: True
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A disadvantage of the relational database management system (RDBMS) is its inability to hide the complexities of the relational model from the user. a. True b. False
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ANSWER: False
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In an SQL-based relational database, each table is dependent on every other table. a. True b. False
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ANSWER: False
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In an SQL-based relational database, rows in different tables are related based on common values in common attributes. a. True b. False
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ANSWER: True
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Each row in the relational table is known as an entity instance or entity occurrence in the ER model. a. True b. False
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ANSWER: True
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M:N relationships are not appropriate in a relational model. a. True b. False
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ANSWER: True
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In Chen notation, entities and relationships have to be oriented horizontally - not vertically. a. True b. False
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ANSWER: False
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Today, most relational database products can be classified as object/relational. a. True b. False
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ANSWER: True
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The network model has structural level dependence. a. True b. False
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ANSWER: True
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The external model is the representation of the database as "seen" by the DBMS. a. True b. False
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ANSWER: False
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The hierarchical model is software-independent. a. True b. False
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ANSWER: False
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The relational model is hardware-dependent and software-independent. a. True b. False
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ANSWER: False
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A(n) _____'s main function is to help one understand the complexities of the real-world environment. a. node b. entity c. model d. database
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ANSWER: c
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A(n) _____ is anything about which data are to be collected and stored. a. attribute b. entity c. relationship d. constraint
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ANSWER: b
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A(n) _____ represents a particular type of object in the real world. a. attribute b. entity c. relationship d. node
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ANSWER: b
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A(n) _____ is the equivalent of a field in a file system. a. attribute b. entity c. relationship d. constraint
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ANSWER: a
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A(n) _____ is bidirectional. a. attribute b. entity c. relationship d. constraint
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ANSWER: c
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A(n) _____ is a restriction placed on the data. a. attribute b. entity c. relationship d. constraint
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ANSWER: d
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_____ are important because they help to ensure data integrity. a. Attributes b. Entities c. Relationships d. Constraints
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ANSWER: d
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_____ are normally expressed in the form of rules. a. Attributes b. Entities c. Relationships d. Constraints
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ANSWER: d
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Students and classes have a _____ relationship. a. one-to-one b. one-to-many c. many-to-one d. many-to-many
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ANSWER: d
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Which of the following is true of business rules? a. They allow the designer to set company policies with regard to data. b. They allow the designer to develop business processes. c. They can serve as a communication tool between the users and designers. d. They provide a framework for the company's self-actualization.
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ANSWER: c
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A noun in a business rule translates to a(n) _____ in the data model. a. entity b. attribute c. relationship d. constraint
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ANSWER: a
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A verb associating two nouns in a business rule translates to a(n) _____ in the data model. a. entity b. attribute c. relationship d. constraint
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ANSWER: c
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In the _____ model, the basic logical structure is represented as an upside-down tree. a. hierarchical b. network c. relational d. entity relationship
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ANSWER: a
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In the _____ model, each parent can have many children, but each child has only one parent. a. hierarchical b. network c. relational d. entity relationship
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ANSWER: a
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The hierarchical data model was developed in the _____. a. 1960s b. 1970s c. 1980s d. 1990s
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ANSWER: a
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In the _____ model, the user perceives the database as a collection of records in 1:M relationships, where each record can have more than one parent. a. hierarchical b. network c. object-oriented d. entity relationship
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ANSWER: b
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The object-oriented data model was developed in the _____. a. 1960s b. 1970s c. 1980s d. 1990s
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ANSWER: c
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VMS/VSAM is an example of the _____. a. hierarchical model b. file system data model c. relational data model d. XML data model
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ANSWER: b
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Oracle 12c, MS SQL Server, and Tamino are examples of _____ data models. a. hierarchical b. file system c. relational d. XML Hybrid
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ANSWER: d
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MySQL is an example of the _____. a. hierarchical model b. file system data model c. relational data model d. XML data model
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ANSWER: c
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A(n) _____ enables a database administrator to describe schema components. a. extensible markup language (XML) b. data definition language (DDL) c. unified modeling language (UML) d. query language
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ANSWER: b
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The relational data model was developed in the _____. a. 1960s b. 1970s c. 1980s d. 1990s
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ANSWER: b
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The _____ model was developed to allow designers to use a graphical tool to examine structures rather than describing them with text. a. hierarchical b. network c. object-oriented d. entity relationship
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ANSWER: d
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A(n) _______ enables a database administrator to describe schema components. a. extensible markup language (XML) b. data definition language (DDL) c. unified modeling language (UML) d. query language
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ANSWER: b
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The _____ model uses the term connectivity to label the relationship types. a. relational b. network c. object-oriented d. entity relationship
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ANSWER: d
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The _____ data model is said to be a semantic data model. a. relational b. network c. object-oriented d. entity relationship
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ANSWER: c
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The _____ data model uses the concept of inheritance. a. relational b. network c. object-oriented d. entity relationship
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ANSWER: c
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Which of the following types of HDFS nodes stores all the metadata about a file system? a. Data node b. Client node c. Name node d. Map node
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ANSWER: c
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Which of the following is true of NoSQL databases? a. They do not support distributed database architectures. b. They are not based on the relational model. c. They are geared toward transaction consistency rather than performance. d. They do not support very large amounts of sparse data.
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ANSWER: b
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Which of the following types of HDFS nodes acts as the interface between the user application and the HDFS? a. Data node b. Client node c. Name node d. Map node
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ANSWER: b
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A(n) _____ is a relatively simple representation of more complex real-world data structures.
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ANSWER: data model
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A(n) _____ is a brief, precise, and unambiguous description of a policy, procedure, or principle within a specific organization.
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ANSWER: business rule
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A(n) _____ in a hierarchical model is the equivalent of a record in a file system.
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ANSWER: segment
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A(n) _____ is the conceptual organization of an entire database as viewed by a database administrator.
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ANSWER: schema
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A(n) _____ defines the environment in which data can be managed and is used to work with the data in the database.
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ANSWER: data manipulation language (DML)
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The relational model's foundation is a mathematical concept known as a(n) _____.
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ANSWER: relation
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Each row in a relation is called a(n) _____.
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ANSWER: tuple
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Each column in a relation represents a(n) _____.
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ANSWER: attribute
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Each row in the relational table is known as a(n) _____.
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ANSWER: entity instance
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In _____, a three-pronged symbol represents the "many" side of the relationship.
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ANSWER: Crow's Foot notation
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A(n) _____ is a collection of similar objects with a shared structure and behavior.
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ANSWER: class
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In object-oriented terms, a(n) _____ defines an object's behavior.
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ANSWER: method
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_____ is a language based on OO concepts that describes a set of diagrams and symbols used to graphically model a system.
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ANSWER: UML (Unified Modeling Language) Unified Modeling Language (UML) Unified Modeling Language UML
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The term _____ is used to refer to the task of creating a conceptual data model that could be implemented in any DBMS.
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ANSWER: logical design
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The _____ is the representation of a database as "seen" by the DBMS.
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ANSWER: internal model
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One of the limitations of the _____ model is that there is a lack of standards.
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ANSWER: hierarchical
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The _____ model is the end users' view of the data environment.
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ANSWER: external
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An internal _____ refers to a specific representation of an internal model, using the database constructs supported by the chosen database.
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ANSWER: schema
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From a database point of view, the collection of data becomes meaningful only when it reflects properly defined _____.
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ANSWER: business rules
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The movement to find new and better ways to manage large amounts of web- and sensor-generated data and derive business insight from it, while simultaneously providing high performance and scalability at a reasonable cost is referred to as "_____."
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ANSWER: Big Data