Appendix #zC #zThe #zUniversity #zLab:
Conceptual #zDesign #zVerification, #zLogical #zDesign, #zand
#zImplementation
Appendix C #z
The University Lab: Conceptual Design, Verification,
#z #z #z #z #z
Logical Design, and Implementation
#z #z #z #z
Discussion Focus #z
How #zis #za #zdatabase #zdesign #zverified, #zand #zwhy #zis #zsuch #zverification #znecessary?
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-user
requirements 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
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.
1
, Appendix #zC #zThe #zUniversity #zLab:
Conceptual #zDesign #zVerification, #zLogical #zDesign, #zand
#zImplementation
The # z use # z of # z system # z modules # z can # z hardly # z be # z overemphasized # z in # z a # z database # z design
# z environment. # z Stress #zthese #zmodule #zcharacteristics #zand #zfeatures:
• Modules #zrepresent #zsubsets #zof #zthe #zdatabase #zmodel: #zSmaller #z"pieces" #zare #zmore #zeasily
#zunderstood.
• Modules #zare #zself-contained #zand #zaccomplish #za #zspecific #zsystem #zfunction; #zif #zsuch #za
#zsystem #zfunction #zmust #zbe #zmodified, #zother #zfunctions #zremain #zunaffected.
• Modules #zfit #zinto #za #zmodular #zdatabase #zdesign, #zwhich #zis #zmore #zeasily #zmodified #zand
#zadapted #zto #znew #zcircumstances. #zBecause #zmodification #zefforts #zare #zfocused #zon #za
#zdatabase #zsubset, #zproductivity #zof #zboth #zdesigners #zand #zapplication #zdevelopers #zis
#zlikely #zto #zbe #zenhanced.
Module #zinterfaces #zmust #zbe #zclear #zif #zthe #zmodules #zare #zexpected #zto #zwork #zwell #zwithin #zthe #zoverall #zsystem.
2
, Appendix #zC #zThe #zUniversity #zLab:
Conceptual #zDesign #zVerification, #zLogical #zDesign, #zand
#zImplementation
Answers to Review Questions
#z #z #z
1. Why #zmust #za #zconceptual #zmodel #zbe #zverified? #zWhat #zsteps #zare #zinvolved #zin #zthe #zverification #zprocess?
The #zverification #zof #za #zconceptual #zmodel #zis #zcrucial #zto #za #zsuccessful #zdatabase #zdesign. #zThe
#zverification #zprocess #zallows #zthe #zdesigner #zto #zcheck #zthe #zaccuracy #zof #zthe #zdatabase #zdesign #zby:
• Re-examining #zdata #zand #zdata #ztransformations.
• Enabling #zthe #zdesigner #zto #zevaluate #zthe #zdesign #zefficiency #zrelative #zto #zthe #zend
#zuser's #zand #zsystem's #zdesign #zgoals.
Keep #zin #zmind #zthat, #zto #za #zlarge #zextent, #zthe #zbest #zdesign #zis #zthe #zone #zthat #zserves #zthe #zend-user
#zrequirements #zbest. #zFor #zexample, #za #zdesign #zthat #zworks #zwell #zfor #za #zmanufacturing #zfirm #zmay
#znot #zfit #zthe #zneeds #zof #za #zmarketing #zresearch #zfirm, #zand #zvice #zversa.
The #zverification #zprocess #zhelps #zthe #zdesigner #zto #zavoid #zimplementation #zproblems #zlater #zby:
• Validating #zthe #zmodel's #zentities. #z(Remember #zthe #zminimal #zdata #zrule.)
• Confirming #zentity #zrelationships #zand #zeliminating #zduplicate, #zunnecessary, #zor
#zimproperly #zdefined #zrelationships.
• Eliminating #zdata #zredundancies.
• Improving #zthe #zmodel's #zsemantic #zprecision #zto #zbetter #zrepresent #zreal-world #zoperations.
• Confirming #zthat #zall #zuser #zrequirements #z(processing, #zperformance, #zor #zsecurity) #zare #zmet.
Verification #zis #za #zcontinuous #zactivity #zin #zany #zdatabase #zdesign. #zThe #zdatabase #zdesign #zprocess #zis
#zevolutionary #zin #znature: #zIt #zrequires #zthe #zcontinuous #zevaluation #zof #zthe #zdeveloping #zmodel #zby
#zexamining #zthe #zeffect #zof #zadding #znew #zentities #zand #zby #zconfirming #zthat #zany #zdesign #zchanges
#zenhance #zthe #zmodel's #zaccuracy.
The #zverification #zprocess #zrequires #zthe #zfollowing #zsteps:
1. Identify #zthe #zdatabase's #zcentral #zentity.
The # z central # z entity # z is # z the # z most # z important # z entity # z in # z our # z database, # z and
# z most # z of # z the # z other #zentities #zdepend #zon #zit.
3
, Appendix #zC #zThe #zUniversity #zLab:
Conceptual #zDesign #zVerification, #zLogical #zDesign, #zand
#zImplementation
2. Identify #zand #zdefine #zeach #zmodule #zand #zits #zcomponents.
The # z designer # z divides # z the # z database # z model # z into # z smaller # z sets # z that # z reflect # z the
# z data # z needs # z of #zparticular #zsystems #zmodules #zsuch #zas #zinventory, #zorders, #zpayroll, #zetc.
3. Identify #zand #zdefine #zeach #zof #zthe #zmodule's #zprocesses.
Specifically, #zthis #z step #z requires #z the #z identification #z and #z definition #zof #z the #z database # z transactions
that #zrepresent #zthe #zmodule's #zreal-world #zoperations.
4
Conceptual #zDesign #zVerification, #zLogical #zDesign, #zand
#zImplementation
Appendix C #z
The University Lab: Conceptual Design, Verification,
#z #z #z #z #z
Logical Design, and Implementation
#z #z #z #z
Discussion Focus #z
How #zis #za #zdatabase #zdesign #zverified, #zand #zwhy #zis #zsuch #zverification #znecessary?
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-user
requirements 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
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.
1
, Appendix #zC #zThe #zUniversity #zLab:
Conceptual #zDesign #zVerification, #zLogical #zDesign, #zand
#zImplementation
The # z use # z of # z system # z modules # z can # z hardly # z be # z overemphasized # z in # z a # z database # z design
# z environment. # z Stress #zthese #zmodule #zcharacteristics #zand #zfeatures:
• Modules #zrepresent #zsubsets #zof #zthe #zdatabase #zmodel: #zSmaller #z"pieces" #zare #zmore #zeasily
#zunderstood.
• Modules #zare #zself-contained #zand #zaccomplish #za #zspecific #zsystem #zfunction; #zif #zsuch #za
#zsystem #zfunction #zmust #zbe #zmodified, #zother #zfunctions #zremain #zunaffected.
• Modules #zfit #zinto #za #zmodular #zdatabase #zdesign, #zwhich #zis #zmore #zeasily #zmodified #zand
#zadapted #zto #znew #zcircumstances. #zBecause #zmodification #zefforts #zare #zfocused #zon #za
#zdatabase #zsubset, #zproductivity #zof #zboth #zdesigners #zand #zapplication #zdevelopers #zis
#zlikely #zto #zbe #zenhanced.
Module #zinterfaces #zmust #zbe #zclear #zif #zthe #zmodules #zare #zexpected #zto #zwork #zwell #zwithin #zthe #zoverall #zsystem.
2
, Appendix #zC #zThe #zUniversity #zLab:
Conceptual #zDesign #zVerification, #zLogical #zDesign, #zand
#zImplementation
Answers to Review Questions
#z #z #z
1. Why #zmust #za #zconceptual #zmodel #zbe #zverified? #zWhat #zsteps #zare #zinvolved #zin #zthe #zverification #zprocess?
The #zverification #zof #za #zconceptual #zmodel #zis #zcrucial #zto #za #zsuccessful #zdatabase #zdesign. #zThe
#zverification #zprocess #zallows #zthe #zdesigner #zto #zcheck #zthe #zaccuracy #zof #zthe #zdatabase #zdesign #zby:
• Re-examining #zdata #zand #zdata #ztransformations.
• Enabling #zthe #zdesigner #zto #zevaluate #zthe #zdesign #zefficiency #zrelative #zto #zthe #zend
#zuser's #zand #zsystem's #zdesign #zgoals.
Keep #zin #zmind #zthat, #zto #za #zlarge #zextent, #zthe #zbest #zdesign #zis #zthe #zone #zthat #zserves #zthe #zend-user
#zrequirements #zbest. #zFor #zexample, #za #zdesign #zthat #zworks #zwell #zfor #za #zmanufacturing #zfirm #zmay
#znot #zfit #zthe #zneeds #zof #za #zmarketing #zresearch #zfirm, #zand #zvice #zversa.
The #zverification #zprocess #zhelps #zthe #zdesigner #zto #zavoid #zimplementation #zproblems #zlater #zby:
• Validating #zthe #zmodel's #zentities. #z(Remember #zthe #zminimal #zdata #zrule.)
• Confirming #zentity #zrelationships #zand #zeliminating #zduplicate, #zunnecessary, #zor
#zimproperly #zdefined #zrelationships.
• Eliminating #zdata #zredundancies.
• Improving #zthe #zmodel's #zsemantic #zprecision #zto #zbetter #zrepresent #zreal-world #zoperations.
• Confirming #zthat #zall #zuser #zrequirements #z(processing, #zperformance, #zor #zsecurity) #zare #zmet.
Verification #zis #za #zcontinuous #zactivity #zin #zany #zdatabase #zdesign. #zThe #zdatabase #zdesign #zprocess #zis
#zevolutionary #zin #znature: #zIt #zrequires #zthe #zcontinuous #zevaluation #zof #zthe #zdeveloping #zmodel #zby
#zexamining #zthe #zeffect #zof #zadding #znew #zentities #zand #zby #zconfirming #zthat #zany #zdesign #zchanges
#zenhance #zthe #zmodel's #zaccuracy.
The #zverification #zprocess #zrequires #zthe #zfollowing #zsteps:
1. Identify #zthe #zdatabase's #zcentral #zentity.
The # z central # z entity # z is # z the # z most # z important # z entity # z in # z our # z database, # z and
# z most # z of # z the # z other #zentities #zdepend #zon #zit.
3
, Appendix #zC #zThe #zUniversity #zLab:
Conceptual #zDesign #zVerification, #zLogical #zDesign, #zand
#zImplementation
2. Identify #zand #zdefine #zeach #zmodule #zand #zits #zcomponents.
The # z designer # z divides # z the # z database # z model # z into # z smaller # z sets # z that # z reflect # z the
# z data # z needs # z of #zparticular #zsystems #zmodules #zsuch #zas #zinventory, #zorders, #zpayroll, #zetc.
3. Identify #zand #zdefine #zeach #zof #zthe #zmodule's #zprocesses.
Specifically, #zthis #z step #z requires #z the #z identification #z and #z definition #zof #z the #z database # z transactions
that #zrepresent #zthe #zmodule's #zreal-world #zoperations.
4
