中山大学软件学院本科生期末考试《数据库系统原理》(A卷)

中山大学软件学院本科生期末考试考试科目：《数据库系统原理》（A 卷学年学期：2014 学年第 3 学期姓名：学院/系：软件学院学号：考试方式：开卷年级专业：考试时长：120 分钟班别：中山大学授予学士学位工作细则》第八条：“考试作弊者，不授予学士学位。”下为试题区域，共 7 道大题，总分 100 分，考生请在答题纸上作答1. (10marks)LetR={A,B,C,D,E,F,G}andF={ABTC,ATC,ATE,BTC,EFTEG,GTF}.Answerthefollowingthreequestions.1) (4marks)ComputetheminimalcoverofF.BTCATCATEEFTGGTF2) (4marks)DecomposeRinto3NFrelations.{B,C},{A,C,E},{E,F,G}and{A,B,D,F}(OR{A,B,D,G})3) (2marks)Isthecompositionin(b2)inBCNF?Brieflyexplainyouranswer.No.For{E,F,G}andGTF,Gisnotacandidatekey.疆中山大学本科生期末考试试卷 n2. (10marks)AssumethereisanemployeedatabaseEmployee(eid:8bytes,ename:16bytes,did:4bytes,email:12bytes),whereeidandenamearerespectivelytheidandnameofanemployeeanddidistheidofthedepartmentinwhichtheemployeeworks.Supposethereare50,000employeerecordsand500departments(i.e.eachdepartmenthas100employeesonaverage).Apagesizeis1,000bytesandapointercosts4bytes.Figure1.AB+TreeStructure1)Whichofthefollowingdescriptionsabouttheinsertionoperationiscorrect?A. TheB+treecontains2levelsafterinsertion.2nodesplitsareneededduringinsertion.TherootnodecontainssearchkeyT5”.B. TheB+treecontains3levelsafterinsertion.1nodesplitisneededduringinsertion.Therootnodecontainssearchkey“20”.C. TheB+treecontains3levelsafterinsertion.2nodesplitsareneededduringinsertion.Therootnodecontainssearchkey“15”.D. TheB+treecontains3levelsafterinsertion.2nodesplitsareneededduringinsertion.Therootnodecontainssearchkey“20”.Answer:C2)Wewanttodeletethedataentrywithsearchkey“7”.Howmanyleafnodesstoreonlytwodatavaluesafterdeletion?A. 2B. 3C. 4D. 5Answer:A5. (20marks)Youaregivenaninitialhashstructurewiththreekeysalreadyinsertedasbelow.Thehashfunctionish(x)=xmod16.DrawfiveextendablehashstructurescorrespondingforeachinsertionofthefollowingsearchkeyvaluesK:7,15,20,37,18.Assumeeachbucketcanholdtwokeysandthesearchkeyvaluesarriveinthegivenorder(i.e.7beingthefirstcomingkeyand18beingthelastone).Youshouldfollowtheconventionusedbylectureslides:binaryhashindicesstartingfromtheleastsignificantbit.(E.g.1istheleastsignificantbitofthe4digitbinarynumber0001.)疆中山大学本科生期末考试试卷 n疆中山大学本科生期末考试试卷 n疆中山大学本科生期末考试试卷 nI!中山大学本科生期末考试试卷|疆中山大学本科生期末考试试卷 nI!中山大学本科生期末考试试卷|