SOLUTION MANUAL
All Chapters Included
Database Systems Design
Implementation and Management
12TH Edition
1
, Appendix C
The University Lab: Conceptual Design, Verification,
Logical Design, and Implementation
Discussion Focus
How is a database design verified, and why is such verification necessary?
Use our detailed answer to question 1 to focus class discussion on
database design verification. Stress that the verification process uses
the initial ER model as a communication tool.
The designer may begin the verification process by describing the
organization's operations to its end users, basing the detailed
description on the initial ER model. Next, explain how the operations
will be supported by the database design. Stress that the design must
support the end-user application views, outputs, and inputs. Points to
be addressed include such questions as:
Is the description accurate? If not, what aspects of the description must be
corrected?
Does the model support the end-user requirements? If not, what
aspects of the end-userrequirements have not been addressed or
have been addressed inadequately?
Keep in mind that even a model that perfectly addresses all initially
determined end user requirements is likely to need adjustments as
those end users begin to understand the ramifications of the database
2
,design's capabilities. In many cases, the end users may learn what the
organization's processes and procedures actually are, thus leading to
new requirements and the perception of new opportunities. The
database designer must keep such likely developments in mind,
especially if (s)he works as a database design consultant. (Anticipation
of such developments must be factored into the contract negotiations
for consulting fees.)
Discuss the role of the system modules.
The use of system modules can hardly be overemphasized in a
database design environment. Stress these module characteristics and
features:
Modules represent subsets of the database model: Smaller
"pieces" are more easilyunderstood.
Modules are self-contained and accomplish a specific system
function; if such a system function must be modified, other
functions remain unaffected.
Modules fit into a modular database design, which is more easily
modified and adapted to new circumstances. Because
modification efforts are focused on a database subset,
productivity of both designers and application developers is
likely to be enhanced.
Module interfaces must be clear if the modules are expected to work well within
the overall system.
3
, Answers to Review Questions
1. Why must a conceptual model be verified? What steps are involved in the
verification process?
The verification of a conceptual model is crucial to a successful
database design. The verification process allows the designer to
check the accuracy of the database design by:
Re-examining data and data transformations.
Enabling the designer to evaluate the design efficiency
relative to the end user's andsystem's design goals.
Keep in mind that, to a large extent, the best design is the one that
serves the end-user requirements best. For example, a design that
works well for a manufacturing firm may not fit the needs of a
marketing research firm, and vice versa.
The verification process helps the designer to avoid implementation problem
later by:
Validating the model's entities. (Remember the minimal data rule.)
Confirming entity relationships and eliminating duplicate,
unnecessary, or improperlydefined relationships.
Eliminating data redundancies.
Improving the model's semantic precision to better represent real-world
operations.
Confirming that all user requirements (processing, performance, or
security) are met.
Verification is a continuous activity in any database design. The
database design process is evolutionary in nature: It requires the
continuous evaluation of the developing model by examining the
4
All Chapters Included
Database Systems Design
Implementation and Management
12TH Edition
1
, Appendix C
The University Lab: Conceptual Design, Verification,
Logical Design, and Implementation
Discussion Focus
How is a database design verified, and why is such verification necessary?
Use our detailed answer to question 1 to focus class discussion on
database design verification. Stress that the verification process uses
the initial ER model as a communication tool.
The designer may begin the verification process by describing the
organization's operations to its end users, basing the detailed
description on the initial ER model. Next, explain how the operations
will be supported by the database design. Stress that the design must
support the end-user application views, outputs, and inputs. Points to
be addressed include such questions as:
Is the description accurate? If not, what aspects of the description must be
corrected?
Does the model support the end-user requirements? If not, what
aspects of the end-userrequirements have not been addressed or
have been addressed inadequately?
Keep in mind that even a model that perfectly addresses all initially
determined end user requirements is likely to need adjustments as
those end users begin to understand the ramifications of the database
2
,design's capabilities. In many cases, the end users may learn what the
organization's processes and procedures actually are, thus leading to
new requirements and the perception of new opportunities. The
database designer must keep such likely developments in mind,
especially if (s)he works as a database design consultant. (Anticipation
of such developments must be factored into the contract negotiations
for consulting fees.)
Discuss the role of the system modules.
The use of system modules can hardly be overemphasized in a
database design environment. Stress these module characteristics and
features:
Modules represent subsets of the database model: Smaller
"pieces" are more easilyunderstood.
Modules are self-contained and accomplish a specific system
function; if such a system function must be modified, other
functions remain unaffected.
Modules fit into a modular database design, which is more easily
modified and adapted to new circumstances. Because
modification efforts are focused on a database subset,
productivity of both designers and application developers is
likely to be enhanced.
Module interfaces must be clear if the modules are expected to work well within
the overall system.
3
, Answers to Review Questions
1. Why must a conceptual model be verified? What steps are involved in the
verification process?
The verification of a conceptual model is crucial to a successful
database design. The verification process allows the designer to
check the accuracy of the database design by:
Re-examining data and data transformations.
Enabling the designer to evaluate the design efficiency
relative to the end user's andsystem's design goals.
Keep in mind that, to a large extent, the best design is the one that
serves the end-user requirements best. For example, a design that
works well for a manufacturing firm may not fit the needs of a
marketing research firm, and vice versa.
The verification process helps the designer to avoid implementation problem
later by:
Validating the model's entities. (Remember the minimal data rule.)
Confirming entity relationships and eliminating duplicate,
unnecessary, or improperlydefined relationships.
Eliminating data redundancies.
Improving the model's semantic precision to better represent real-world
operations.
Confirming that all user requirements (processing, performance, or
security) are met.
Verification is a continuous activity in any database design. The
database design process is evolutionary in nature: It requires the
continuous evaluation of the developing model by examining the
4
