SSD7数据库系统选择题答案.docx

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1、Mu1.tip1.e-ChoiceQuiz11. nE-Commercesystemconsistsofthefo1.1.owingcomponents.Whichofthesesamecomponentsmustbeinc1.udedinadatabase?(C)hcdata,suchasntbrmatonaboutthegoodsavai1.ab1.etorsa1.e,customers,ordersp1.aced,shippinginibnnation,etc.Adatabasemustinc1.udeaco1.1.ectionofprograms(hatcontro1.thedata,

2、suchasprogramscreate,maintain,andmanipu1.atethedata.Theseprogramscanbeeasi1.yusedtocreate,11ain1.ain,andmampu1.atcdatainotherdomains.Adatabasemustinc1.udeaco1.1.ectionofprogramsthatoperateontbedata,butarcspecifictotheE-Comniercesystem.T1.ieseprogramsenab1.eusers(obrowseIhrOUgh1.hestore-items,p1.aceo

3、rders,trackshipping,etc.(a) IJI.andIII(b) Iand11on1.y()Ion1.y(d)I1.on1.y2. AnE-Commcrccdatabasecontainsdataaboutcustomers,products,orders,systemresponsetimes,etc.WhichofIhefo1.1.owingcanbespecifiedasintegrityconstraintsinan-11)cr.daUbasesystem?(d)NotwoproductscanhavethesameproductID.TheDBMSresponset

4、imefora1.1.VVcbrequestsshou1.dbeatmost2seconds.Acustomerordercannothavemorethanoneshippingaddress.（八）Ion1.y(b)1.I1.andII1.(c) IandIIon1.y(d) 1amiIIIon1.yFeedback:Theconstraints1.IIand111specifytheapp1.icationsemanticsofthedatacapturedintheE-Commcrccdatabase.ConstraintIII.a1.thoughitseemscontrar,toco

5、mmonsense,isnotsomethingthatcanbeprohibitedby(heDBMSbecausetheDBMSisgenera1.purpose.TheresponsetimeoftheDBMScannotbeenforcedbytheDBMS.ItdependsonfactorssuchIheprocessorspeed,memoryavai1.ab1.e,etc.3AnE-Commcrccsystemconsistsofthefo1.1.owingcomponents.Whichofthesesamecomponentswi1.1.constitutea、)、I1.1

6、d)Thedata,suchasinformationaboutthegoodsavai1.ab1.eibrsa1.e.CUS1.Om6.ordersp1.aced,shippinginfb11nation.etc.Aco1.1.ectionofprogramsthatcontro1.thedata,suchasprogramstocreate,maintain,andmanipu1.atethedataconstitutesadatabasesystem.Theseprogramscanbeeasi1.yused(ocreate,maintain,andmanipu1.a1.cdat

7、ainotherdomainssuchasina1.ibraryinformationsystem.Aco1.1.ectionofprogramsthatoperateonthedata,butarcspecifictotheE-commerccsystem,constitutesadatabasesystem.Theseprogramsenab1.euserstobrowsethroughthestore-items,p1.aceorders,(rackshipping,etc.(a) IandI1.on1.y(b) 11on1.y(c) Ion1.y(d) hII.andIIIFeedba

8、ck:databasesysteminc1.udesthedata,theDBMS,andtheapp1.ication-specificprogramsthatoperateonthatdata.5. Inadatabasesystem,whoseresponsibi1.ityisit(oprovidedataconsistency?(d)(a) thedatabaseadministrators(b) theUSerS(c) theapp1.icationprogrammers(d)(heDBMS6. Adatabaseisneededforwhichofthefo1.1.owingapp

9、1.icationsccna11os?(b)Avideostorethatneedstokeeptrackofdataaboutmembers,aboutvideoscarriedbythestore,aboutvideosrentedbymembers.aswe1.1.asdataconcerningborrow-date,re11bdate.andpaymentin11nation.InthehumanresourcesdepartmentOfacompany,informationaboutemp1.oyees,theirtit1.es,theirsa1.ariesandsickdays

10、andabouvacationdaystakenbyeachemp1.oyee.Acomputer-simu1.atedvideogamewhichneedstoca1.cu1.ateanddisp1.ay,thephysica1.(x.y)IOCdIionofeachactorinthegame,thespeedwithwhichtheyarc11odngatthecunentinstant,thedirectioninwhichtheyarcmoving,theactiontheyarcperforming,theang1.eatwhichthegame-p1.ayerisviewing

11、thescene.(a) IandIIIon1.y(b) IandI1.on1.y(c) 1.I1.and111(d) 1on1.y7. Thephysica1.storageS1.ruc1.urcwi1.1.betotheapp1.icbyexamp1.erce11ito(b)(a) aqucr)forSQ1.examp1.es(b) avisua1.query1.anguagedeve1.opedbyIBM()examp1.eSQ1.queriesprovidedbyotherusersthatcanbeInOdifkdtosuitcurrentneeds(d)examp1.eSQ1.qu

12、eriesprovidedbytheDBMSthatuserscuntofstoragespacetobea1.1.ocated(oIhetab1.e(b) thenameofthetab1.eandthenamesofthetab1.esattributes(c) thenameofthetab1.e,thenamesofthetab1.c,sattributes,thedatatypesofthetab1.c,sattributes,thetbmatsofthetab1.esattributes,andthemaximumnumberofrowsthatthetab1.ecanhave(d

13、) thenameofthe(ab1.e,thenamesof(hetab1.esattributes,thedatatypesofaributes.andtheformatsofattributes12. Whatcanbespecifiedinthese1.ectionconditionofaSE1.ECTstatement?（八）(a) aBoo1.eanoperation(b) theconditionsunderwhichthestatementshou1.dbeexecuted(c) thetimeatWh1.Chthese1.ectionshou1.dbeperformed(d)

14、 anarithmeticoperation13. Whichofthefo1.1.owingSQ1.Statemen1.scanbeusedtomodifyjustonerow(outofmanyrows)inatab1.e?(c)(a) A1.TER(b) MODIFY(OUPDATE(d)CHANGE14. Ade1.etionoperationwi1.1.ifthede1.etion1.eadsto(hevio1.ationofatvfetvntia1.integrityconstraint.(C)(a) succeedwithwarning(b) succeedwithoutwarn

15、ing(c) fai1.(d) crashthesystem15. Whichofthefo1.1.owingSQ1.statementscanbeusedtocreateare1.ationa1.tab1.e?(b)(a) APPEND(b) CREATE(c)DD(d)INSERT16. WithQueryByExamp1.e,aUSCrentersaquerj,by(b)(a) typingasyntactica1.1.ycorrectSQ1.querythatusesco1.umnandtab1.enamessimi1.artothecorrectco1.umnandtab1.enam

16、esinadatabase(b) fi1.1.inginske1.etontab1.esOfIhedatabasewithexamp1.esofWha1.iSIOberetrieved(c) p1.acingSQ1.keywords,suchasse1.ect,undertheco1.umnnamestheywanttoretrieve(d) writinganEng1.ishdcscnptionofthedatathattheuserneeds17. DM1.isused(o(d)(a)manipu1.atetheS1.nictureofdatabaseapp1.ications.(b) s

17、pecifythestructureofadatabase.(c) addandde1.etetab1.es.(d) add,nx1.ifyde1.etedatainthedatabase.18. Ajomoperationjoinstab1.esinto.（八）(a) two,one(b) three,two(c) (bur.two(d) three,one/union/intcrscct/cxccpt参加运匏的关系必须相容即含右相同的属性集)19. Adiervnceoperationcanbeapp1.iediotab1.esthat(b)(a) havethesameco1.umnna

18、mes(b) arcunioncompatib1.e(c) arcthesamesize(d) havetheSamCname20. Whichofthetb1.1.owingSQ1.statementscanbeusedtoremovearowfromatab1.e?(c)(a) REMOVE(b) ERASE(ODE1.ETE(d)DESR()YMu1.tip1.e-ChoiceQuiz31. InSQ1.onefunctionoftheASoperatoristo(c)(a) contro1.theorderinwhichaquerysrowsarcsorted(b) definethe

19、domainofanattribute(c) customizethenamesofco1.umnsinaquerysresu1.t(d) 1.imitthecardina1.ityofare1.ation2. Whenremovingatab1.efrom(heschema*usingtheRESTRICToptionwou1.d（八）(a) removethetab1.eiftherearenoreferencestoit(b) removethetab1.eanda1.1.othertab1.esthatthespecifiedtab1.erefersto(c) removethe(ab

20、1.eanda1.1.referencestoit(d) recursive1.yrvnovcIhe(ab1.eanda1.1.othertab1.esthattheremoved(ab1.erefersto3. InSQ1.,adatabasecanbedestroyedbywhichofthefo1.1.owing?（八）(a) thecommandDROPSCHEMA(b) (hecommandDE1.ETEDATABASE(C)thecommandDESTROYDATABASE(d)aseriesofDESIROYIAB1.Ecommands4. Whenastringwhose1.e

21、ngthisstricdy1.essthannisenteredastheva1.ueofafie1.dwhoseSQ1.datatypeisVARCHAR(n),thesystemrespondsby(b)(a) re-promptingfortheentryofastringwhose1.engthisexact1.yn.(b) storingthestringasis.(c) Paddingtheendof(hesiringwithNU1.1.characters1。1.engthnbetbrstoringi(.(d) paddingtheendofthestringwithspaces

22、to1.engthnbeforestoringit.5. InSQ1.,whendestroyingadatabase,theRESTRICToptionremoves(b)(a) everythinginthespecifieddatabase:Ihedata,schema,c.(b) theschemaifthedatabasehasnodataUniptytab1.es)(c) thedataandschemafromthespecifieddatabase,butnotfromre1.ateddatabases(d) thedatabutnottheschema6. InSQ1.ada

23、tabasecanbecreatedbywhichOfIhCfo1.1.owing?(d)(a) asenesOreREATETAB1.Ecommands(b) thecommandADDDATABASE(c) thecommandINSERTDATABASE(d) thecommandCREATESCHEMA7. InaFROMc1.auseofaSE1.ECTstatementinSQ1.,atab1.ecanbea1.iasedwithwhichofthefo1.1.owingoperators?(b)(a) A1.IAS(b) AS(C)RENAME(d)X.InSQ1.,whicho

24、fthefo1.1.owingc1.ausescanbeusedtosortresu1.tsinascendingordescendingorderofattributeva1.ues?(c)(a) SORT(b) GROUPBY(C)ORDERBy(d)ARRANGEBY9.WhenSPCCifyingase1.ectioncriterioninSQ1.attributescanberenamedwihwhichofthetb1.1.owmgoperators?(d)（八）A1.IAS(b)(c) RENAME(d) AS10. InSQ1.whichofthefo1.1.owingoper

25、atorscanbeusedtoexpresssearchesthattestforarangeinase1.ectioncondition?（八）(a) BETWEEN(b) RANGE()STARTandEND(d)FROMandTOMu1.tip1.e-ChoiceQuiz41. Whichofthefo1.1.owingistrueaboutUpdatcabi1.ityofviews?（八）(a) Aviewisupdateab1.eifitinvo1.vesonetab1.eandcontainsakey.(b) Aviewisupdateab1.eifitinvo1.vesmu1.

26、tip1.etab1.esandnokeys.(c) AViCWiSupdateab1.eifitinvo1.vesonetab1.eanddoesnotcontainakey.(d) Aviewisnotupdateab1.eunderanycircumstance.2. Avertica1.viewa1.1.owsusersaccessto(d)(a) on1.ythesystemtab1.es(b) on1.yspecificrowsofthedefiningtab1.es(c) on1.ytheusertab1.es(d) on1.yspecificco1.umnsofthedefin

27、ingtab1.es3. Ahorizonta1.viewa1.1.owsusersaccessto（八）(a) on1.yspecificrowsofthedefiningtab1.es(b) on1.yspecificco1.umnsofthedefiningcab1.es(c) on1.ythesystemtab1.es(d) on1.ythebasetab1.es4. Consider(wotab1.es.EmPIOyeC(En1.PNo.Name.Dcp1.No)andDepartmenUDeptNo.Nanw.Manager)withprimarykeysbeingEmpNoand

28、DcptNorespective1.y.TheDeptNoattributeoftheEmp1.oyeetab1.ehasaN()NU1.1.constraintandisaforeignkeythatreferencestheDcptNoattributeoftheDepartmenttab1.e.TheManagerattributeoftheDePartmCINtab1.ehasaNOTNU1.1.constraintandisaforeignkeythatreferencestheEmpNoattributeoftheEmp1.oyeetab1.e.Whenthetab1.esaree

29、mpty,theon1.ywaytoinsertrowsintothetwotab1.esis(d)(a) touseatransactioninNOTDEFERRAB1.Emode(b) touseatransactioneitherinDEFERRAB1.EmodeorinNOTDEFERRAB1.Emode()nottouseatransactiona(a1.1.(d)touseatransactioninDEFERRAB1.Emode5. TheSQ1.keywordmakesthemodificationsofthetransactionpermanent,whi1.etheSQ1.

30、keyworddiscardsthenx1.ificationsofthetransaction,(b)(a) WRITE.ABORT(b) COMMIT.RO1.1.BCK(c) UPDATE,SE1.ECT(d) SAVE,CANCE1.6. Whichofthefo1.1.owingcommandscanbeusedtogiveaccesspermissionstoatab1.e?（八）(a) GRANT(b) AUTHORIZE(C)PERMIT(d)A1.1.OW7. Whocana1.waysgiveaccesspermissionstoatab1.e?(b)(a) on1.yth

31、esuper-user(b) theownerofthetab1.e(c) theUscrofthctabic(d) on1.ythedatabaseadministrator(DBA)8. Whichofthefo1.1.owingcommandscanbeusedtoremoveaccessprivi1.egesassociatedwithatab1.e?（八）(a) REVOKE(b) DENY(c) RETRACr(d) REMOVE9. WhenisembeddedSQ1.referredtoasstaticSQ1.?(d)(a) whentheSQ1.statementscanne

32、verbechanged(b) whentheembeddedSQ1.operatesonthestaticpanofthedatabase(C)whenIheembeddedSQ1.a1.waysreturnsIheSameseofresu1.ts(d)whentheembeddedSQ1.istrans1.atedintoDBMSpi1.e-time10. WhenisembeddedSQ1.referredtoasdynamicSQ1.?（八）(a) whentheembeddedSQ1.istrans1.atedintoDBMSca1.1.satrun-time(b) whenthee

33、mbeddedSQ1.operatesonthedynamicpartofthedatabase(c) whentheembeddedSQ1.a1.waysreturnsdficrcntsetsofresu1.ts(d) whentheSQ1.statementsarcchangedincvcr,run11. Whichofthefo1.1.owingistrueaboutviewsbeinguptodate?（八）(a) Viewsarca1.waysuptodate.(b) Viewscanbeautomatica1.1.ymadeuptodateperiodica1.1.ybythesy

34、stem.()Viewsareneveruptodate;thereisa1.waysa1.agtime.(d) Viewsarcuptodateon1.yaftertheSynchruniza1.ionoperationbytheuser.12. Whichofthefo1.1.owingrcicrcntia1.1.ytriggeredactionsarcsupportedinSQ1.whenareferentia1.integrityconstraintisvio1.ated?（八）SETNU1.1.REJECTCASCADESETDEFAU1.T(a) 1.III.andIVon1.y(

35、b) I1.and111on1.y(C)IandIVon1.y(d)1.II.andIIIon1.y13. Whichofthefo1.1.owingistrueaboutUpdatcabi1.ityofviews?(c)(a) Aviewisnotupdateab1.eifitinvo1.vesonetab1.eandcontainsakey.(b) Aviewisupdateab1.eundera1.1.circumstances.(c) viewisnotupdateab1.eifitinvo1.vesaggregatefunctionsandnestedqueries.(d) Avie

36、wisnotupdateab1.eunderanycircumstance.Mu1.tip1.e-ChoiceQuiz51. InanERmode1.,whatisarecursivere1.ationshiptype?(d)(a) ThetypeOfrc1.ationshipthatdocsnotbe1.onganywhere(b) never-endingtypeofre1.ationship(c) There1.ationshiptypewherethere1.atedentitiesareoneandthesame(d) Thetypeofre1.ationshipbetweenent

37、itiesofoneentitytype2. InanERmode1.,(hecardina1.ityratioofare1.ationshiptypeis(b)(a) thenumberofinstancesofre1.ationshipsofthatre1.ationshiptype(b) thenumberofre1.ationshipsofthatre1.ationshiptypeinwhichanentitycanparticipate(c) theminimumnumberofentitiesthatcanparticipateinthatre1.ationshiptype(d)

38、henumberofentitytypesinvo1.vedinthatre1.ationshiptype3. Whichofthetb1.1.owngistrueaboutstoragefordc11vcdatt11butcs?(b)(a) Derivedattributesmustnotbestored.(b) Derivedauributesausua1.1.ynotstoredbecausetheycanbecomputed.(c) Derivedattributesmustbestored.(d) Derivedattributesarcusua1.1.ystoredbecause

39、storageimprovesrcricva1.performance.4. Aweakentitytypeimp1.iesa(C)(a) re1.ationshipwithpartia1.participationconstraint(b) strongre1.ationshiptype(c) re1.ationshipwithtota1.participationconstraint(d) weakre1.ationshiptype5. IntheEntity-Re1.ationshipmode1.,propertiesthatcharacterizeentitiesandre1.atio

40、nshipsarcmode1.edas(c)(a) weakentities(b) entitytypes(c) attributes(d) pa11icipationconstraints6. IntheEn1.i1.y-Rc1.ationshipmode1.,aderivedattributeisone(c)(a) thatiscomposedofmu1.tip1.eatomicattributes(b) thatmayhavemu1.tip1.eva1.uessimu1.taneous1.y()whosev*a1.uecanbecomputedfromtheva1.uesofothera

41、11ributes(d) thatcharacterizesare1.ationshipinsteadofanentity7. InanERmode1.,whichofthefo1.1.owingistrueaboutacomponentattribute?(b)(a) AComponen1.attributea1.wayscontainsothercomponents.(b) componenta1.1.ributccanbeacompositeattribute.(c) componentattributeisa1.waysatomic.(d) Componentattributesmus

42、ta1.waysbecombinedbyanaggregationoperation.8. InERmode1.ing,genera1.izationistheprocessofgenerating(b)(a) entitiesoutofattributes(b) superc1.assesoutOfsubc1.asscs(c) subc1.assesoutofsuperc1.asses(d) attributesoutofentities9. Whichofthefo1.1.owingistrueaboutattributesinare1.ationa1.mode1.?(d)Anributescanbenuhiva1.ucd.Attributescnbecomposite.(a) I1.on1.y(b) Neither1norI1.()Ion1.y(d)Bo1.hIandI1.10. WhenmappingfromanERmode1.toare1.ationa1.mode1.,astrongentityismappedintoa(d)（八）row(b) co1.umn(c) key(d) tab1.e11. IntheEntity-Re1.ationshipmode1