计算机专业文献翻译关于数据库.docx

计算机专业文献翻译关于数据库.docx

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计算机专业文献翻译关于数据库

（1）AHISTORICALPERSPECTIVE

Fromtheearliestdaysofcomputers,storingandmanipulatingdatahavebeenamajorapplicationfocus.Thefirstgeneral-purposeDBMSwasdesignedbyCharlesBachmanatGeneralElectricintheearly1960sandwascalledtheIntegratedDataStore.Itformedthebasisforthenetworkdatamodel,whichwasstandardizedbytheConferenceonDataSystemsLanguages（CODASYL）andstronglyinfluenceddatabasesystemsthroughthe1960s.BachmanwasthefirstrecipientofACM’sTuringAward（thecomputerscienceequivalentofaNobelprize）forworkinthedatabasearea;hereceivedtheawardin1973.

Inthelate1960s,IBMdevelopedtheInformationManagementSystem（IMS）DBMS,usedeventodayinmanymajorinstallations.IMSformedthebasisforanalternativedatarepresentationframeworkcalledthehierarchicaldatamodel.TheSABREsystemformakingairlinereservationswasjointlydevelopedbyAmericanAirlinesandIBMaroundthesametime,anditallowedseveralpeopletoaccessthesamedatathroughcomputernetwork.Interestingly,todaythesameSABREsystemisusedtopowerpopularWeb-basedtravelservicessuchasTravelocity!

In1970,EdgarCodd,atIBM’sSanJoseResearchLaboratory,proposedanewdatarepresentationframeworkcalledtherelationaldatamodel.Thisprovedtobeawatershedinthedevelopmentofdatabasesystems:

itsparkedrapiddevelopmentofseveralDBMSsbasedontherelationalmodel,alongwitharichbodyoftheoreticalresultsthatplacedthefieldonafirmfoundation.Coddwonthe1981TuringAwardforhisseminalwork.Databasesystemsmaturedasanacademicdiscipline,andthepopularityofrelationalDBMSschangedthecommerciallandscape.Theirbenefitswerewidelyrecognized,andtheuseofDBMSsformanagingcorporatedatabecamestandardpractice.

Inthe1980s,therelationalmodelconsolidateditspositionasthedominantDBMSparadigm,anddatabasesystemscontinuedtogainwidespreaduse.TheSQLquerylanguageforrelationaldatabases,developedaspartofIBM’sSystemRproject,isnowthestandardquerylanguage.SQLwasstandardizedinthelate1980s,andthecurrentstandard,SQL-92,wasadoptedbytheAmericanNationalStandardsInstitute（ANSI）andInternationalStandardsOrganization（ISO）.Arguably,themostwidelyusedformofconcurrentprogrammingistheconcurrentexecutionofdatabaseprograms（calledtransactions）.Userswriteprogramsasiftheyaretoberunbythemselves,andtheresponsibilityforrunningthemconcurrentlyisgiventotheDBMS.JamesGraywonthe1999TuringawardforhiscontributionstothefieldoftransactionmanagementinaDBMS.

Inthelate1980sandthe1990s,advanceshavebeenmadeinmanyareasofdatabasesystems.Considerableresearchhasbeencarriedoutintomorepowerfulquerylanguagesandricherdatamodels,andtherehasbeenabigemphasisonsupportingcomplexanalysisofdatafromallpartsofanenterprise.Severalvendors（e.g.,IBM’sDB2,Oracle8,InformixUDS）haveextendedtheirsystemswiththeabilitytostorenewdatatypessuchasimagesandtext,andwiththeabilitytoaskmorecomplexqueries.Specializedsystemshavebeendevelopedbynumerousvendorsforcreatingdatawarehouses,consolidatingdatafromseveraldatabases,andforcarryingoutspecializedanalysis.

Aninterestingphenomenonistheemergenceofseveralenterpriseresourceplanning（ERP）andmanagementresourceplanning（MRP）packages,whichaddasubstantiallayerofapplication-orientedfeaturesontopofaDBMS.WidelyusedpackagesincludesystemsfromBaan,Oracle,PeopleSoft,SAP,andSiebel.Thesepackagesidentifyasetofcommontasks（e.g.,inventorymanagement,humanresourcesplanning,financialanalysis）encounteredbyalargenumberoforganizationsandprovideageneral

applicationlayertocarryoutthesetasks.ThedataisstoredinarelationalDBMS,andtheapplicationlayercanbecustomizedtodifferentcompanies,leadingtolowerIntroductiontoDatabaseSystems

overallcostsforthecompanies,comparedtothecostofbuildingtheapplicationlayerfromscratch.Mostsignificantly,perhaps,DBMSshaveenteredtheInternetAge.WhilethefirstgenerationofWebsitesstoredtheirdataexclusivelyinoperatingsystemsfiles,theuseofaDBMStostoredatathatisaccessedthroughaWebbrowserisbecomingwidespread.QueriesaregeneratedthroughWeb-accessibleformsandanswersareformattedusingamarkuplanguagesuchasHTML,inordertobeeasilydisplayedinabrowser.AllthedatabasevendorsareaddingfeaturestotheirDBMSaimedatmakingitmoresuitablefordeploymentovertheInternet.Databasemanagementcontinuestogainimportanceasmoreandmoredataisbroughton-line,andmadeevermoreaccessiblethroughcomputernetworking.Todaythefieldisbeingdrivenbyexcitingvisionssuchasmultimediadatabases,interactivevideo,digitallibraries