数据库复习题71755文档格式.docx

数据库复习题71755文档格式.docx

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4．Inthefollowingproperties,theonethatdoesnotbelongtodatabaseapproachis.

A．highdatasharingB．improveddataintegrity

C．highdataredundancyD．improveddataindependence

5．Indatabasesystems,dataindependencemeansthat.

A．theimmunityofapplicationprogramstochangesofthedatavalue

B．theimmunityofapplicationprogramstochangesofthedataamounts

C．theimmunityofapplicationprogramstochangesofthedatastructure

D．theimmunityofthedatastoragestructuretochangesofthedatastorageapproach

6．ThepersonwhomanagesthedataresourceinvolvedinDBisreferredtoas.

A．DBAB．EMBAC．MBAD．DA

7．Thepersonwhoisresponsibleforthephysicalrealizationofthedatabaseisreferredtoas.

8．containsthegloballogicalrepresentationoftheentiredatabase.

A．ConceptualschemaB．Internalschema

C．ExternalschemaD．Physicalschema

9．Itisthatensuresthedataindependenceindatabasesystem.

A．theschemaandtheexternalschema

B．theschemaandtheinternalschema

C．thetwomappingsbetweenthethreelevelofschemas

D．thethreelevelofschemas

10．Itisthatensuresthelogicaldataindependenceindatabasesystem.

A．themappingsbetweenconceptualschemaandexternalschemas

B．themappingbetweenconceptualschemaandinternalschema

C．theconceptualschema

11．Thedescriptionofthedatabaselogicalstructurethatcanbeseenbybothusersandapplicationprogramsiscalled.

A．conceptualschemaB．internalschema

C．externalschemaD．physicalschema

12．WhichofthefollowingtasksisnotadutyofDBA.

A．definingintegrityconstraintsB．definingdatabaseschema

C．managingdatabasesecurityD．designingdatabasemanagementsystem

13．WhichofthefollowingoperationsisnotsupportedbyDML

A．insertingsomerowsintoatableB．deletingsomerowsfromatable

C．findingsomerowsfromatableD．creatingsometablesinadatabase

14．WhichofthefollowingoperationsisnotsupportedbyDDL

A．creatingsomeviewsinadatabaseB．modifyingtablestructuresinadatabase

15．Amongobject-baseddatamodels,themostfamousoneis.

A．entity-relationshipdatamodelB．semanticdatamodel

C．relationaldatamodelD．functionaldatamodel

16．Adatamodelcomprisesthreecomponents,theyare.

A．theexternalschema,theconceptualschemaandtheinternalschema

B．therelations,thetuplesandtheprimarykeys

C．thestructuralpart,themanipulativepartandtheintegrityrules

D．themeaningofmodel,theoperationalrulesandtheimplementationlanguage

17．Thedatainahierarchicaldatamodelisof.

A．atreestructureB．adirectedgraphstructure

C．alinearstructureD．atabularstructure

18．Thedatainanetworkdatamodelisof.

19．Arelationaldatamodelisthemostimportantmodelthatiscomposedof.

A．therelationaldatastructure,therelationaloperationsandtheintegrityconstraints

C．theentityintegrity,thereferentialintegrityandtheuser-definedintegrity

D．theexternalschema,theconceptualschemaandtheinternalschema

20．Ifwequeryinadatabasebasedona,weneedonlytoexpresswhatandnothow.

A．hierarchicaldatamodelB．networkdatamodel

C．relationaldatamodelD．physicaldatamodel

21．Whichofthefollowingistrueindatabasesystems

A．DBMSrunsconcurrentlywithOS.B．DBMSandOScalleachother.

C．OScallsDBMS.D．DBMScallsOS.

22．Indesigningfile-basedsystems,asthemainproblemisthedesignofsystemfunctions,amongthefollowingworks,themostimportantoneis.

A．designingdatastructureB．programming

C．memoryarrangementD．informationstorage

23．Thecoreoftheinformationprocessingbasedondatabasesystemsis.

A．thediskB．programC．thedataD．thememory

24．Indatabasesystem,theconversionbetweenlogicaldataandphysicaldatacanbedoneby.

A．applicationprogramsB．theOSC．theDBMSD．I/Ofacilities

25．Thereisamongthethree-levelschemasofadatabasesystem.

A．integrityB．consistencyC．structuralconsistencyD．agreatdifference

26．Thethree-levelarchitectureofdatabasesystemsisthethree-levelabstractionsfor.

A．memoriesB．dataC．programsD．disks

27．Amongthethree-levelschemasofdatabasesystems,thenearestonefromthesecondarystorageis.

A．theexternalschemasB．theconceptualschema

C．thesubschemasD．theinternalschema

28．Itisjustbecausethatthereisdataindependenceindatabasesystems.

A．thedisk-basedstorageB．thethree-levelschemas

C．thedataaccessbycallingOSD．thevisualizedprogramminglanguage

29．Indatabasesystems,therelationbetween‘dataindependence’and‘datarelationship’isthat.

A．theyareirrelevantconceptsB．theyaresimultaneouslytrueorfalse

C．theformerinfersthelatterD．theycaninfereachother

30．Indatabasesystem,‘dataindependence’meansthat.

A．thisdataisindependentonthatdata

B．applicationprogramsareindependentonthedatabasestructure

C．diskisindependentonmemory

D．dataisindependentondisk

B.Fillinblankswithproperwordsorphrases

1．Databasereferstoa（a）collectionof（b）data,andthe（c）ofthisdata,designedtomeettheinformationneedsofanorganization.

2．Anentityisa（a）thatistoberepresentedinthedatabase;

anattributeisa（b）ofanentity;

arelationshipisan（c）betweenentities

3．WecanidentifyfivemajorcomponentsintheDBMSenvironment.Theyare（a）,（b）,（c）,（d）and（e）.

4．DBMSreferstoasoftwaresystemthatenablesusersto（a）,（b）,and（c）thedatabase,andthatprovides（d）tothisdatabase.

5．Typically,DBMSprovidesthefollowingfacilities:

（a）,（b）,（c）and（d）.

6.ThecontrolledaccesstodatabaseofDBMSmayinclude:

（a）,（b）,（c）,（d）and（e）.

7.Thethree-levelschemaarchitectureofdatabaseincludes:

（a）,（b）,（c）,wheretheremaybemultiple（d）inadatabase,butthereareonlyone（e）and（f）inadatabase.

8.Rolesinthedatabaseenvironmentinclude:

9.Aconceptualschemaofdatabasecontainsa（a）oftheentiredatabase,whichincludes:

allentities,their（b）,andtheir（c）;

（d）ondata;

semanticinformationaboutdata;

（e）and（f）information.

10.Logicaldataindependencereferstotheimmunityof（a）tochangesin（b）.Thatis:

changesin（c）donotrequiretomodify（d）and（e）.Thisisguaranteedby（f）mappings.

11.Physicaldataindependencereferstotheimmunityof（a）tochangesin（b）.Thatis:

changesin（c）donotrequiretomodify（d）.Thisisguaranteedby（e）mapping.

12.Datamodelreferstoanintegratedcollectionofconceptsfordescribing（a）,（b）,and（c）.Adatamodelcomprisesthreecomponents:

（d）,（e）and（f）.

13.Categorizedbytheabstractlevelsofdata,thereare3categoriesofdatamodels,theyare:

（a）,（b）and（c）.

14.Object-baseddatamodelsinclude（a）,（b）,（c）and（d）.

15.Record-baseddatamodelsinclude（a）,（b）and（c）.

16.Multi-userDBMSarchitecturesinclude（a）,（b）and（c）.

Chapter3~4

1．Whichoneofthefollowingisnotthepropertyofrelations

A．Eachattributehasadistinctdatatype.B．Eachattributehasadistinctname.

C．Orderofrowshasnosignificance.

D．Orderofcolshasnosignificance.

2．Inrelationalmodels,eachrelationcanonlyhaveone.

A．candidatekeyB．foreignkeyC．innerkeyD．primarykey

3．Inrelationalmodels,eachcandidatekey.

A．canonlyhaveatleasttwoattributesB．canonlyhaveatmostoneattributes

C．mayhaveoneormoreattributesD．mustcontainalltheattributesoftherelation

4．GivenarelationschemaRanditsattributesX,ifXreferencesacandidatekeyYofrelationschemaS,thenwecall.

A．XisaforeignkeyofrelationschemaSB．YisaforeignkeyofrelationschemaR

C．XisaforeignkeyofrelationschemaRD．YisaforeignkeyofrelationschemaS

5．SupposeSetD1,D2andD3haveK1,K2andK3elements,respectively,thenthenumberoftuplesinD1D2D3willbe______.

A．K1K2K3B．K1+K2+K3C．（K1+K2）K3D．（K1+K2）÷

K3

6．SpecialrelationaloperationsthatarelationalDBMSshouldsupportinclude:

.

A．sorting,indexingandstatisticaloperationB．selection,projectionandjoin

C．association,updateandsortingD．display,print,tabulation

7．Betweenrelationschemaandrelationaldatabaseschema,whichofthe