Chapter 2 - Data Management - |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
Foundations.
Discuss the importance of data modeling. - correct answer✔✔Explanation: A data model is a
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
relatively simple representation, usually graphical, of a more complex real world object event.
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
The data model's main function is to help us understand the complexities of the real-world
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
environment. The database designer uses data models to facilitate the interaction among |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
designers, application programmers, and end users. In short, a good data model is a |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
communications device that helps eliminate (or at least substantially reduce) discrepancies |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
between the database design's components and the real world data environment. The |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
development of data models, bolstered by powerful database design tools, has made it |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
possible to substantially diminish the database design error potential. (Review Section 2.1 in
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
detail.)
What is a business rule, and what is its purpose in data modeling? - correct
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
answer✔✔Explanation: A business rule is a brief, precise, and unambigous description of a |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
policy, procedure, or principle within a specific organization's environment. In a sense, business
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
rules are misnamed: they apply to any organization -- a business, a government unit, a
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
religious group, or a research laboratory; large or small -- that stores and uses data to generate
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
information.
How do you translate business rules into data model components? - correct
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
answer✔✔Explanation: As a general rule, a noun in a business rule will translate into an entity |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
in the model, and a verb (active or passive) associating nouns will translate into a relationship
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
among the entities. For example, the business rule "a customer may generate many invoices"
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
contains two nouns (customer and invoice) and a verb ("generate") that associates them.
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
Describe the basic features of the relational data model and discuss their importance to the
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
end user and the designer. - correct answer✔✔Explanation: A relational database is a single
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
data repository that provides both structural and data independence while maintaining
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
conceptual simplicity. |||\\\
, Question : Explain how the entity relationship (ER) model helped produce a more structured
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
relational database design environment. - correct answer✔✔Explanation: An entity |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
relationship model, also known as an ERM, helps identify the database's main entities and their |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
relationships. Because the ERM components are graphically represented, their role is more
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
easily understood. Using the ER diagram, it's easy to map the ERM to the relational database
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
model's tables and attributes. This mapping process uses a series of well-defined steps to
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
generate all the required database structures. |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
Why is an object said to have greater semantic content than an entity? - correct
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
answer✔✔Explanation: An object has greater semantic content because it embodies both data |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
and behavior. That is, the object contains, in addition to data, also the description of the
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
operations that may be performed by the object. |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
What is the difference between an object and a class in the object oriented data model
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
(OODM)? - correct answer✔✔Explanation: An object is an instance of a specific class. It is|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
useful to point out that the object is a run-time concept, while the class is a more static
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
description.
What is an ERDM, and what role does it play in the modern (production) database
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
environment? - correct answer✔✔Explanation: The Extended Relational Data Model (ERDM) is |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
the relational data model's response to the Object Oriented Data Model (OODM.) Most
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
current RDBMSes support at least a few of the ERDM's extensions. For example, support for
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
large binary objects (BLOBs) is now common.
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
What is a relationship, and what three types of relationships exist? - correct
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
answer✔✔Explanation: A relationship is an association among (two or more) entities. Three |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
types of relationships exist: one-to-one (1:1), one-to-many (1:M), and many-to-many (M:N or
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
M:M.)
Give an example of each of the three types of relationships.
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
1:1
Foundations.
Discuss the importance of data modeling. - correct answer✔✔Explanation: A data model is a
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
relatively simple representation, usually graphical, of a more complex real world object event.
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
The data model's main function is to help us understand the complexities of the real-world
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
environment. The database designer uses data models to facilitate the interaction among |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
designers, application programmers, and end users. In short, a good data model is a |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
communications device that helps eliminate (or at least substantially reduce) discrepancies |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
between the database design's components and the real world data environment. The |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
development of data models, bolstered by powerful database design tools, has made it |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
possible to substantially diminish the database design error potential. (Review Section 2.1 in
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
detail.)
What is a business rule, and what is its purpose in data modeling? - correct
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
answer✔✔Explanation: A business rule is a brief, precise, and unambigous description of a |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
policy, procedure, or principle within a specific organization's environment. In a sense, business
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
rules are misnamed: they apply to any organization -- a business, a government unit, a
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
religious group, or a research laboratory; large or small -- that stores and uses data to generate
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
information.
How do you translate business rules into data model components? - correct
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
answer✔✔Explanation: As a general rule, a noun in a business rule will translate into an entity |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
in the model, and a verb (active or passive) associating nouns will translate into a relationship
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
among the entities. For example, the business rule "a customer may generate many invoices"
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
contains two nouns (customer and invoice) and a verb ("generate") that associates them.
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
Describe the basic features of the relational data model and discuss their importance to the
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
end user and the designer. - correct answer✔✔Explanation: A relational database is a single
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
data repository that provides both structural and data independence while maintaining
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
conceptual simplicity. |||\\\
, Question : Explain how the entity relationship (ER) model helped produce a more structured
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
relational database design environment. - correct answer✔✔Explanation: An entity |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
relationship model, also known as an ERM, helps identify the database's main entities and their |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
relationships. Because the ERM components are graphically represented, their role is more
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
easily understood. Using the ER diagram, it's easy to map the ERM to the relational database
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
model's tables and attributes. This mapping process uses a series of well-defined steps to
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
generate all the required database structures. |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
Why is an object said to have greater semantic content than an entity? - correct
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
answer✔✔Explanation: An object has greater semantic content because it embodies both data |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
and behavior. That is, the object contains, in addition to data, also the description of the
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
operations that may be performed by the object. |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
What is the difference between an object and a class in the object oriented data model
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
(OODM)? - correct answer✔✔Explanation: An object is an instance of a specific class. It is|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
useful to point out that the object is a run-time concept, while the class is a more static
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
description.
What is an ERDM, and what role does it play in the modern (production) database
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
environment? - correct answer✔✔Explanation: The Extended Relational Data Model (ERDM) is |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
the relational data model's response to the Object Oriented Data Model (OODM.) Most
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
current RDBMSes support at least a few of the ERDM's extensions. For example, support for
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
large binary objects (BLOBs) is now common.
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
What is a relationship, and what three types of relationships exist? - correct
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
answer✔✔Explanation: A relationship is an association among (two or more) entities. Three |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
types of relationships exist: one-to-one (1:1), one-to-many (1:M), and many-to-many (M:N or
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
M:M.)
Give an example of each of the three types of relationships.
|||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\
1:1
