MySQL 数据库系统设计实现与管理第六版课后习题答案Part 7 Review Questions and Exercises

Word可编辑Word可编辑SOLUTIONSTOREVIEWQUESTIONSANDEXERCISESFORPART7–OBJECTDBMSs(CHAPTERS27–28)SolutionstoReviewQuestionsandExercises3Chapter27Object-OrientedDBMSs–ConceptsandDesign11Chapter28Object-OrientedDBMSs:StandardsandSystemsChapter27Object-OrientedDBMSs–ConceptsandDesignReviewQuestions27.1DescribethethreegenerationsofDBMSs.FirstgenerationisthehierarchicalandnetworkDBMSs.SecondgenerationistherelationalDBMSs.Thirdgenerationistheobject-orientedandobject-relationalDBMSs.SeeSection27.1.27.2Compareandcontrastthedifferentdefinitionsofobject-orienteddatamodels.DiscussionofdefinitionsprovidedinSection27.2.1.27.3Describethemainmodelingprimitivesofthefunctionaldatamodel.Themainmodelingprimitivesareentitiesandfunctionalrelationships(seeSection27.2.2).27.4WhatisapersistentprogramminglanguageandhowdoesitdifferfromanOODBMS?Alanguagethatprovidesitsuserswiththeabilityto(transparently)preservedataacrosssuccessiveexecutionsofaprogram,andevenallowssuchdatatobeusedbydifferentprograms(seeSection27.2.3).MaindifferencebetweenPPLandOODBMSisthattheOODBMStendstoprovidemoreDBMS-relatedservices.27.5Discussthedifferencebetweenthetwo-levelstoragemodelusedbyconventionalDBMSsandthesingle-levelstoragemodelusedbyOODBMSs.SeeSection27.3.27.6Howdoesthissingle-levelstoragemodelaffectdataaccess?SeeSection27.3.27.7Describethemainstrategiesthatcanbeusedtocreatepersistentobjects.Checkpointing,serialization,andexplicitpaging.Explicitpagingincludesreachability-basedandallocation-basedpersistence(seeSection27.3.3).27.8Whatispointerswizzling?Discussthedifferentapproachestopointerswizzling.ActionofconvertingOIDstomainmemorypointers(SeeSection27.3.1).27.9Describethetypesoftransactionprotocolthatcanbeusefulindesignapplications.SeeSections27.4.1and22.4.27.10Discusswhyversionmanagementmaybeausefulfacilityforsomeapplications.Therearemanyapplicationsthatneedaccesstothepreviousstateofanobject.Forexample,thedevelopmentofaparticulardesignisoftenanexperimentalandincrementalprocess,thescopeofwhichchangeswithtime.Itisthereforenecessaryindatabasesthatstoredesignstokeeptrackoftheevolutionofdesignobjectsandthechangesmadetoadesignbyvarioustransactions.SeeSection27.4.2.27.11Discusswhyschemacontrolmaybeausefulfacilityforsomeapplications.Engineeringdesignisanincrementalprocessandevolveswithtime.Tosupportthisprocess,applicationsrequireconsiderableflexibilityindynamicallydefiningandmodifyingthedatabaseschema.Forexample,itshouldbepossibletomodifyclassdefinitions,theinheritancestructure,andspecificationsofattributesandmethodswithoutrequiringsystemshutdown.SeeSection27.4.3.27.12DescribethedifferentarchitecturesforanOODBMS.SeeSection27.4.4.27.13ListtheadvantagesanddisadvantagesofanOODBMS.SeeSection27.5.27.14DescribehowrelationshipscanbemodelledinanOODBMS.SeethediscussiononSection27.6.2.27.15DescribethedifferentmodellingnotationsintheUML.Expectdiscussionofthenotationsfor:·Structuraldiagrams,whichdescribethestaticrelationshipsbetweencomponents,andinclude:·classdiagrams,·objectdiagrams,·componentdiagrams,·deploymentdiagrams.·Behavioraldiagrams,whichdescribethedynamicrelationshipsbetweencomponents,andinclude:·usecasediagrams,·sequencediagrams,·collaborationdiagrams,·statechartdiagrams,·activitydiagrams.Exercises27.16FortheDreamHomecasestudydocumentedinAppendixA,suggestattributesandmethodsthatwouldbeappropriateforBranch,Staff,andPropertyForRentclasses.Theattributesshouldbesimilartothosedocumentedinthetextbook.Thestudentwouldbeexpectedtocomeupwithstandardget/setmethods,suchasGetStaffSalary,PutStaffSalary,andthenmethodsforregisteringnewpropertiesforrent,newowners,newclients,appointmentsforviewings,andsoon.27.17ProduceusecasediagramsandasetofassociatedsequencediagramsfortheDreamHomecasestudydocumentedinAppendixA.Studentsshouldusethe“DataTransactions”sectionsofAppendixAtoderivealistofusecases.ThediagramsshouldbesimilartothoseseeninFigure27.20forusecasesand27.21forsequencediagrams.InSectionA.1theactorisBranchUser,andinSectionA.2theactorisStaffUser.27.18ProduceusecasediagramsandasetofassociatedsequencediagramsfortheUniversityAccommodationOfficecasestudydocumentedinAppendixB.1.Studentsshouldusethe“QueryTransactions”sectionsofAppendixB.1toderivealistofusecases.ThediagramsshouldbesimilartothoseseeninFigure27.20forusecasesand27.21forsequencediagrams.Theactorisadministrativeuser.27.19ProduceusecasediagramsandasetofassociatedsequencediagramsfortheEasyDriveSchoolofMotoringcasestudydocumentedinAppendixB.2.Studentsshouldusethe“QueryTransactions”sectionsofAppendixB.2toderivealistofusecases.ThediagramsshouldbesimilartothoseseeninFigure27.20forusecasesand27.21forsequencediagrams.Theactorisadministrativeuser.27.20ProduceusecasediagramsandasetofassociatedsequencediagramsfortheWellmeadowsHospitalcasestudydocumentedinAppendixB.3.Studentsshouldusethe“TransactionRequirements”sectionsofAppendixB.3toderivealistofusecases.ThediagramsshouldbesimilartothoseseeninFigure27.20forusecasesand27.21forsequencediagrams.Theactorishospitalworker.27.21YouhavebeenaskedbytheManagingDirectorofDreamHometoinvestigateandprepareareportontheapplicabilityofanOODBMSforyourorganization.ThereportshouldcomparethetechnologyoftheRDBMSwiththatoftheOODBMS,andshouldaddresstheadvantagesanddisadvantagesofimplementinganOODBMSwithintheorganization,andanyperceivedproblemareas.Finally,thereportshouldcontainafullyjustifiedsetofconclusionsontheapplicabilityoftheOODBMSforDreamHome.Awell-presentedreportisexpected.Justificationmustbegivenforanyrecommendationsmade.27.22FortherelationalHotelschemaintheExercisesattheendofChapter4,suggestanumberofmethodsthatwouldbeapplicabletothesystem.Produceanobject-orientedschemaforthesystem.Somemethodsmightbe:createNewHoteldestroyHotelchangeHotelNamegetHotelNamecreateNewRoomdestroyRoomchangeRoomPricechangeRoomTypegetRoomPricegetRoomTypecreateNewGuestdestroyGuestchangeGuestNamechangeGuestAddressgetGuestNamegetGuestAddresscreateNewBookingdestroyBookingchangeRoomNumberchangeDatesgetDateFromgetDateTo27.23FortherelationalProjectschemaintheExercisesattheendofChapter5,suggestanumberofmethodsthatwouldbeapplicabletothesystem.Produceanobject-orientedschemaforthesystem.27.24FortherelationalLibraryschemaintheExercisesattheendofChapter5,suggestanumberofmethodsthatwouldbeapplicabletothesystem.Produceanobject-orientedschemaforthesystem.27.25Produceanobject-orienteddatabasedesignfortheDreamHomecasestudydocumentedinAppendixA.Stateanyassumptionsnecessarytosupportyourdesign.ThestudentshouldproduceamodelsimilartoFigure16.9withsomemethodsadded.Youmayprefertogetthestudenttodothisparticularexerciseintwoparts:onetoproduceanobject-orienteddesignfortheStaffviewandonefortheBranchview.27.26Produceanobject-orienteddatabasedesignfortheUniversityAccommodationOfficecasestudypresentedinAppendixB.1.Stateanyassumptionsnecessarytosupportyourdesign.ThestudentshouldproduceamodelsimilartothatgiveninthesolutiontoExercise16.16withsomemethodsadded.27.27Produceanobject-orienteddatabasedesignfortheEasyDriveSchoolofMotoringcasestudypresentedinAppendixB.2.Stateanyassumptionsnecessarytosupportyourdesign.ThestudentshouldproduceamodelsimilartothatgiveninthesolutiontoExercise16.18withsomemethodsadded.27.28Produceanobject-orienteddatabasedesignfortheWellmeadowsHospitalcasestudypresentedinAppendixB.3.Stateanyassumptionsnecessarytosupportyourdesign.ThestudentshouldproduceamodelsimilartothatgiveninthesolutiontoExercise16.21withsomemethodsadded.Again,youmayprefertogetthestudenttodothisparticularexercisebasedontheparticularviewsthathavebeenidentified(ChargeNurse,Director,andPersonnel).27.29RepeatExercises27.22to27.28butproduceaschemausingthefunctionaldatamodel.Diagramaticallyillustrateeachschema.(a)Hotelcasestudy.(b)UniversityAccommodationOfficecasestudySamplesolutionasfollows(onlyprimarykeyshown):UsingtheabovetwodiagramsasexemplarsandthesolutionstoExercises27.23and25.28,shouldberelativelystraightforwardtocreatethediagramsfortheremainingcasestudies.27.30UsingtherulesforschemaconsistencygiveninSection27.4.3andthesampleschemagiveninFigure27.11,considereachofthefollowingmodificationsandstatewhattheeffectofthechangeshouldbetotheschema:(a)addinganattributetoaclass(b)deletingandattributefromaclass(c)renamingandattribute(d)MakingaclassSasuperclassofaclassC(e)removingaclassSfromthelistofsuperclassesofaclassC(f)creatinganewclassC(g)deletingaclass(h)modifyingclassnames.SeeSection27.4.3.Chapter28Object-OrientedDBMSs:StandardsandSystemsReviewQuestions28.1DiscussthemainconceptsoftheODMGObjectModel.Giveanexampletoillustrateeachoftheconcepts.TheODMGOMisasupersetoftheOMGOMandspecifiesthefollowingbasicmodelingprimitives:·Thebasicmodelingprimitivesaretheobjectandtheliteral.Onlyanobjecthasauniqueidentifier.·Objectsandliteralscanbecategorizedintotypes.Allobjectsandliteralsofagiventypeexhibitcommonbehaviorandstate.Atypeisitselfanobject.Anobjectissometimesreferredtoasaninstanceofitstype.·Behaviorisdefinedbyasetofoperationsthatcanbeperformedonorbytheobject.Operationsmayhavealistoftypedinput/outputparametersandmayreturnatypedresult.·Stateisdefinedbythevaluesanobjectcarriesforasetofproperties.Apropertymaybeeitheranattributeoftheobjectorarelationshipbetweentheobjectandoneormoreotherobjects.Typically,thevaluesofanobject’spropertiescanchangeovertime.·AnODMSstoresobjects,enablingthemtobesharedbymultipleusersandapplications.AnODMSisbasedonaschemathatisdefinedintheObjectDefinitionLanguage(ODL),andcontainsinstancesofthetypesdefinedbyitsschema.SeeSection28.2.2.28.2WhatisthefunctionoftheODMGObjectDefinitionLanguage?ODLisalanguagefordefiningthespecificationsofobjecttypesforODMG-compliantsystems,equivalenttotheDataDefinitionLanguage(DDL)oftraditionalDBMSs.ItsmainobjectiveistofacilitateportabilityofschemasbetweencompliantsystemswhilehelpingtoprovideinteroperabilitybetweenODMSs.TheODLdefinestheattributesandrelationshipsoftypesandspecifiesthesignatureoftheoperations,butitdoesnotaddresstheimplementationofsignatures.ThesyntaxofODLextendstheInterfaceDefinitionLanguage(IDL)oftheCORBA.TheODMGhopethattheODLwillbethebasisforintegratingschemasfrommultiplesourcesandapplications.SeeSection28.2.3.28.3WhatisthefunctionoftheODMGObjectQueryLanguage?ODMGOQLisusedtospecifyhowdatabaseobjectsareretrievedandmanipulatedwithintheapplicationprogram(seeSection28.2.4).28.4HowdoestheODMGGROUPBYclausedifferfromtheSQLGROUPBYclause?Giveanexampletoillustrateyouranswer.TheOQLGROUPBYhasbeenextendedtoprovideanexplicitreferencetothecollectionofobjectswithineachgroup(whichinOQLiscalledapartition).SeeExample28.6.28.5HowdoestheODMGaggregatefunctionsdifferfromtheSQLaggregatefunctions?Giveanexampletoillustrateyouranswer.TheOQLaggregatefunctionscanbeappliedwithintheselectclauseortotheresultoftheselectoperation.Forexample,thefollowingtwoexpressionsareequivalentinOQL:SELECTCOUNT(s)FROMsINsalesStaffWHEREs.WorksAt.branchNo=‘B003’;COUNT(SELECTsFROMsINsalesStaffWHEREs.WorksAt.branchNo=‘B003’);Note,OQLallowsaggregatefunctionstobeappliedtoanycollectionoftheappropriatetypeand,unlike,SQL,canbeusedinanypartofthequery.SeeExample28.5.28.6WhatisthefunctionoftheODMGObjectInterchangeFormat?TheObjectInterchangeFormat(OIF)isaspecificationlanguageusedtodumpandloadthecurrentstateofanODMStoandfromoneormorefiles.OIFcanbeusedtoexchangepersistentobjectsbetweenODMSs,seeddata,providedocumentation,anddrivetestsuites.SeeSection28.2.5.28.7BrieflydiscusshowtheODMGC++languagebindingworks.ACclasslibraryisprovidedcontainingclassesandfunctionsthatimplementtheODLconstructs.Inaddition,OML(ObjectManipulationLanguage)isusedtospecifyhowdatabaseobjectsareretrievedandmanipulatedwithintheapplicationprogram.Tocreateaworkingapplication,theCODLdeclarationsarepassedthroughaCODLpreprocessor,whichhastheeffectofgeneratingaCheaderfilecontainingtheobjectdatabasedefinitionandstoringtheODMSmeta-datainthedatabase.Theuser’sCapplication,whichcontainsOML,isthencompiledinthenormalwayalongwiththegeneratedobjectdatabasedefinitionCheaderfile.Finally,theobjectcodeoutputbythecompilerislinkedwiththeODMSruntimelibrarytoproducetherequiredexecutableimage.SeeSection28.2.5.Exercises28.8Maptheobject-orienteddesignfortheHotelcasestudyproducedinExercise27.22totheODMGODL.classHotel{(extenthotelskeyhotelNo)attributestringhotelNo;attributestringhotelName;attributestringcity;relationshipset<Room>ContainsinverseRoom::ContainedIn;…}classRoom{(extentroomskeyhotelNo,roomNo)attributestringhotelNo;attributestringroomNo;attributestringhotelName;attributestringcity;relationship<Hotel>ContainedIninverseHotel::Contains;relationshipset<Booking>GetsinverseBooking::MadeFor;changeRoomPrice(inroomNo:string,infloat)raises(noSuchRoom);changeRoomType(inroomNo:string,inchar)raises(noSuchRoom);…}classGuest{(extentguestskeyguestNo)attributestringguestNo;attributestringguestName;attributestringguestAddress;relationshipset<Booking>MakesinverseBooking::MadeFor;…}classBooking{(extentbookingskey(hotelNo,guestNo,dateFrom))attributestringhotelNo;attributestringguestNo;attributedatedateFrom;attributedatedateTo;attributestringroomNo;relationship<Room>MadeForinverseRoom::Gets;relationshipGuestMadeForinverseGuest::Makes;createNewBooking(inHotel,inGuest,inRoom)raises(noSuchHotel,noSuchGuest,hotelFull)changeRoomNumber();changeDates();…}ShowhowthefollowingquerieswouldbewritteninOQL:(a)Listallhotels.hotelortosortthem:sorthINHotelbyh.name(b)Listallsingleroomswithapricebelow£20.00pernight.SELECTh.roomsFROMhINhotelWHEREh.rooms.price<20(c)Listthenamesandaddressesofallguests.SELECTSTRUCT(name:g.name,address:g.address)FROMgINguest(d)ListthepriceandtypeofallroomsattheGrosvenorHotel.typeprices{attributeprice:float;type:char;}prices(SELECTSTRUCT(price:h.rooms.price,type:h.rooms.type)FROMhINhotelWHEREh.name=‘GrosvenorHotel’(e)ListallguestscurrentlystayingattheGrosvenorHotel.SELECTgFROMgINguestsbINg.booked_forhINb.booking_forWHEREb.dateFrom<=‘01-01-05’ANDb.dateTo>=‘01-01-05’ANDh.name=‘GrosvenorHotel’(substitute‘01-01-05’fortoday’sdate).(f)ListthedetailsofallroomsattheGrosvenorHotel,includingthenameofthegueststayingintheroom,iftheroomisoccupied.defineoccupiedasSELECTSTRUCT(h.rooms,SELECTg.nameFROMgINguestbINg.booked_forhINb.booking_forWHEREb.dateFrom<=‘01-01-15’ANDb.dateTo>=‘01-01-15’ANDh.name=‘GrosvenorHotel’)FROMhINhotelUNIONSELECTSTRUCT(h.rooms,nil)FROMhINhotel,yINoccupiedWHEREh.rooms.roomNo!=y.roomNo(substitute‘01-01-15’fortoday’sdate).(g)Listtheguestdetails(guestNo,nameandaddress)ofallguestsstayingattheGrosvenorHotel.SELECTSTRUCT(guestNo:g.guestNo,name:g.name,address:g.address)FROMgINgINguestbINg.booked_forhINb.booking_forWHEREb.dateFrom<=‘01-01-15’ANDb.dateTo>=‘01-01-15’ANDh.name=‘GrosvenorHotel’(substitute‘01-01-15’fortoday’sdate).28.11Maptheobject-orienteddatabasedesignfortheDreamHomecasestudyproducedinExercise27.25totheODMGODL.Partialsolutionasfollows:classBranch{(extentbrancheskeybranchNo)attributestringbranchNo;attributestructBranchAddress{stringstreet,stringcity,stringpostcode}address;attributelist<string>telNo[3];relationshipset<Registration>RegistersinverseClient::IsRegisteredWith;relationshipStaffHasinverseStaff::WorksIn;relationshipManagerIsManagedByinverseManager::Manages;relationshipset<PropertyForRent>OffersinversePropertyForRentIsOfferedBy;}classPerson{attributestructPName{stringfName,stringlName}name;}classStaffextendsPerson{(extentstaffkeystaffNo)attributestringstaffNo;attributeenumSetType{M,F}sex;attributedateDOB;attributeenumPositionType{Manager,Supervisor,Assistant}position;attributefloatsalary;relationshipBranchWorksIninverseBranch::Has;relationshipset<PropertyForRent>OverseesinversePropertyForRent::IsOverseenBy;relationshipset<Registration>ProcessesinverseRegistration::IsProcessedBy;relationshipset<Staff>SupervisesinverseStaff::SupervisedBy;increaseSalary(inStaff,infloat)raises(noSuchPerson);overseeProperty(inStaff,inPropertyForRent)raises(noSuchPerson,noSuchProperty);moveBranch(inStaff,infrom::Branch,into::Branch)raises(noSuchPerson,noSuchBranch);}classManagerextendsStaff{(extentmanagers)attributedatemgrStartDate;attributefloatbonus;relationshipBranchManagesinverseBranch::IsManagedBy;}classPropertyForRent{(extentrentalskeypropertyNo)attributestringpropertyNo;attributestructPropertyAddress{stringstreet,stringcity,stringpostcode}address;attributestringtype;attributeintegerrooms;attributefloatrent;relationshipStaffIsOverseenByinverseStaff::Oversees;relationshipBranchIsOfferedByinverseBranch::Offers;relationshipset<Advert>PlacedIninverseAdvert::Advertises;relationshipOwnerIsOwnedByinverseOwner::Owns;relationshipset<Viewing>TakesinverseViewing::IsTakenBy;relationshipset<Lease>LeasedByinverseLease::LeaseFor;rentOut(inPropertyForRent)raises(noSuchProperty);}classClientextendsPerson{(extentclientskeyclientNo)attributestringclientNo;attributestringtelNo;attributestringprefType;attributefloatmaxRent;relationshipRegistrationAgreesinverseRegistration::RegistrationFor;relationshipset<Viewing>RequestsinverseViewing::IsRequestedBy;relationshipset<Lease>HoldsinverseLease::IsHeldBy;rentProperty(inClient,inPropertyForRent)raises(noSuchClient,noSuchProperty);register(inClient,inBranch)raises(noSuchClient,noSuchBranch);arrangeViewing(inClient,inPropertyForRent)raises(noSuchClient,noSuchProperty);}28.12Maptheobject-orienteddatabasedesignfortheUniversityAccommodationOfficecasestudyproducedinExercise27.26totheODMGODL.Usingtheobject-orienteddesignproducedinExercise27.26andtherelationalschemagiveninthesolutiontoExercise17.10,thentheanswercaneasilybederivedinasimilarmannertothetwosolutionsaboveandthesolutiontoExercise28.14below.28.13Maptheobject-orienteddatabasedesignfortheEasyDriveSchoolofMotoringcasestudyproducedinExercise27.27totheODMGODL.Usingtheobject-orienteddesignproducedinExercise27.27andtherelationalschemagiveninthesolutiontoExercise17.11,thentheanswercaneasilybederivedinasimilarmannertothetwosolutionsaboveandthesolutiontoExercise28.14below.28.14Maptheobject-orienteddatabasedesignfortheWellmeadowscasestudyproducedinExercise27.28totheODMGODL.Thefollowingisasampleschema,notallmethodsareshown:classWard{(extentwardskeywardNo)attributestringwardNo;attributestringwardName;attributestringlocation;attributeintegertotalBeds;attributestringtelExtn;relationshiplist<WaitingList>HasWaitingListinverseWaitingList::IsWaitingFor{order_byWaitingList::listDate,wardReq};relationshiplist<StaffRota>HasStaffRotainverseStaffRota::OnShiftFor{order_byStaffRota::wardNo,weekNo};relationshipset<Requisition>ReceivesinverseRequisition::ReqFor;relationshipNurseIsChargeNurseForinverseNurse::ChargeFor;assignChargeNurse(inNurse)raises(noSuchNurse);}classPerson{attributestructPName{stringfName,stringlName}name;attributestringaddress;attributestringtelNo;attributedateDOB;attributecharsex;}deftypestructQualification{dateqDate,stringqType,stringinstitutionName;}deftypestructWorkExperience{datesDate,datefDate,stringposition,stringorgName;}classStaffextendsPerson{(extentstaffkeystaffNo,NIN)attributestringstaffNo;attributestringNIN;attributestringposition;attributefloatsalary;attributeintegersScale;attributeintegerweekHrs;attributecharcontType;attributechartypePay;attributeset<Qualification>qualifications;attributeset<WorkExperience>experience;relationshiplist<StaffRota>HasRotainverseStaffRota::ShiftFor{order_byStaffRota::staffNo,weekNo};increaseSalary(inStaff,infloat);}classNurseextendsStaff{(extentnurses)relationshipWardChargeForinverseWard::IsChargeNurseFor;relationshipset<Requisition>MakesinverseRequisition::IsMadeBy;makeRequisition(inNurse,inPharmaceutical)raises(noSuchDrug);}classConsultantextendsStaff{(extentconsultants)relationshiplist<Appointment>SeesinverseAppointment::IsSeenBy{order_byAppointment::consS