搜索
外文原文DatabaseDevelopmentProcessBasedoninformationengineeringinformationsystemsplanningdatabaseisasourceofdevelopmentprojects.Thesenewdatabasedevelopmentprojectsisusuallyinordertomeetthestrategicneedsoforganizations,suchasimprovingcustomersupport,improveproductandinventorymanagement,oramoreaccuratesalesforecast.However,manymoredatabasedevelopmentprojectisthebottom-upapproachemerging,suchasinformationsystemuserneedsspecificinformationtocompletetheirwork,thusbeginningaprojectrequest,andasotherinformationsystemsexpertsfoundthatorganizationsneedtoimprovedatamanagementandbeginnewprojects.Bottom-upeveninthecircumstances,tosetupanenterprisedatamodelisalsonecessarytounderstandtheexistingdatabasecanprovidethenecessarydata,otherwise,thenewdatabase,dataentitiesandattributescanbeaddedtothecurrentdataresourcestotheorganization.Boththestrategicneedsoroperationalinformationneedsofeachdatabasedevelopmentprojectsnormallyconcentratedinadatabase.Someprojectsonlyconcentratedinthedatabasedefinition,designandimplementationofadatabase,asafollow-uptothebasisofthedevelopmentofinformationsystems.However,inmostcases,thedatabaseandassociatedinformationprocessingfunctionasacompleteinformationsystemsdevelopmentprojectwaspartofthedevelopment.one.SystemDevelopmentLifeCycleGuidemanagementinformationsystemdevelopmentprojectsisthetraditionalprocessofsystemdevelopmentlifecycle(SDLC).SystemdevelopmentlifecycleisanorganizationofthedatabasedesignersandprogrammersinformationsystemcomposedofthePanelofExpertsdetaileddescription,development,maintenanceandreplacementoftheentireinformationsystemsteps.ThisprocessisbecauseWaterfallthanforeverystepintotheadjacentthenextstep,thatis,theinformationsystemisaspecificationdevelopedbyapieceofland,everypieceoftheoutputisunderaninput.Howevershowninthefigure,thesestepsarenotpurelylinear,eachofthestepsoverlapintime(andthuscanmanageparallelsteps),butwhentheneedtoreconsiderpreviousdecisions,butalsotorollbacksomestepsahead.(Andthereforewatercanbeputbackinthewaterfall!)Thesystemdevelopmentlifecycleincludingeachstageanddatabasedevelopment-relatedactivities,therefore,thequestionofdatabasemanagementsystemsthroughouttheentiredevelopmentprocess.InFigure5werepeatofthesystemdevelopmentlifecyclestageoftheseven,andoutlinesthecommondatabaseateachstageofdevelopmentactivities.Pleasenotethatthesystemsdevelopmentlifecyclestagesanddatabasedevelopmentstepsexistsbetweentherelationshipbetweentheconceptofmodelingdatainbothsystemsdevelopmentlifecyclestagesbetween.1.1EnterpriseModelingDatabasedevelopmentprocessfromtheenterprisemodeling(systemdevelopmentlifecyclestageoftheprojectfeasibilitystudies,andtochooseapart)Organizationssetthescopeandgeneraldatabasecontent.Enterprisemodelingininformationsystemsplanningandotheractivities,theseactivitiesdeterminewhichpartofinformationsystemsneedtochangeandstrengthentheentireorganizationandoutlinesthescopeofdata.Inthisstep,checkthecurrentdatabaseandinformationsystems,developmentoftheprojectasthemainareasofthenatureofthebusiness,withaverygeneraldescriptionofeachterminthedevelopmentofinformationsystemswhenneededdata.Eachitemonlywhenitachievedtheexpectedgoalsoforganizationscanbewhenthenextstep.1.2ConceptualDataModelingOnehasalreadybegunontheInformationSystemproject,theconceptofdatamodelingphaseoftheinformationsystemsneedsofallthedata.Itisdividedintotwostages.First,itbegantheprojectintheplanningstage.Atthesametimeoutliningtheestablishmentofotherdocumentstotheexistingdatabasewithoutconsideringthecircumstancesspecificdevelopmentprojectsinthescopeoftherequireddata.Thiscategoryonlyincludeshigh-leveldata(entities),andmaincontact.Theninthesystemdevelopmentlife-cycleanalysisstagemusthaveamanagementinformationsystemsettheentireorganizationDetailsofthedatamodeldefinitionofalldataattributes,listingalldatatypesthatalldatainter-entitybusinesslinkages,definingdescriptionofthefulldataintegrityrules.Intheanalysisphase,butalsotheconceptofinspectiondatamodel(alsocalledtheconceptbehindthemodel)andthegoalofinformationsystemsusedtoexplainotheraspectsofthemodelofconsistencycategories,suchasprocessingsteps,rulesanddataprocessingtimeoftiming.However,eveniftheconceptissuchdetaileddatamodelisonlypreliminary,becausefollow-upinformationsystemlifecycleactivitiesinthedesignofservices,statements,displayandinquiriesmayfindthatmissingelementormistakes.Therefore,theconceptofdataoftensaidthatmodelingisatop-downmanner,itsareasofoperationfromthegeneralunderstandingofthedriver,ratherthanthespecificinformationprocessingactivitiesbythedriver.1.3LogicalDatabaseDesignLogicaldatabasedesignfromtwoperspectivesdatabasedevelopment.First,theconceptofdatamodeltransformintorelationaldatabasetheorybasedonthecriteriathatmeans-between.Then,asthedesignofinformationsystems,everycomputerprocedures(includingproceduresfortheinputandoutputformat),databasesupportservices,statements,andinquiriesrevealedthatadetailedexamination.Inthisso-calledBottom-upanalysis,accurateverificationoftheneedtomaintainthedatabaseandthedataineachaffairs,statementsandsoontheneedsofthoseinth