会员注册 | 登录 | 微信快捷登录 支付宝快捷登录 QQ登录 微博登录 | 帮助中心 人人文库renrendoc.com美如初恋!
站内搜索 百度文库

热门搜索: 直缝焊接机 矿井提升机 循环球式转向器图纸 机器人手爪发展史 管道机器人dwg 动平衡试验台设计

   首页 人人文库网 > 资源分类 > DOC文档下载

外文翻译---改进ADO.NET性能.doc

  • 资源星级:
  • 资源大小:101.50KB   全文页数:9页
  • 资源格式: DOC        下载权限:注册会员/VIP会员
您还没有登陆,请先登录。登陆后即可下载此文档。
  合作网站登录: 微信快捷登录 支付宝快捷登录   QQ登录   微博登录
友情提示
2:本站资源不支持迅雷下载,请使用浏览器直接下载(不支持QQ浏览器)
3:本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰   

外文翻译---改进ADO.NET性能.doc

附录1.英文资料ImprovingADO.NETPerformanceImproving.NETApplicationperformanceandscalabilitySummaryThischapterprovidesprovenstrategiestohelpyoudesignanddevelopscalabledataaccesssolutions.Topicscoveredincludedifferenttechniquestopassdataacrossapplicationlayers,managingthedatabaseconnectionpool,optimizingstoredprocedurecalls,reducingdatasetserializationcost,techniquesforpagingthroughlargeresultsets,managingtransactions,handlingBLOBS,andmuchmore.ObjectivesOptimizeyourdataaccessdesign.ChoosebetweenDataSetsandDataReaders.Runefficientdatabasecommands.Passdatabetweenlayersefficiently.Performefficienttransactions.Optimizeconnectionmanagement.Evaluatethecostofpagingthroughrecords.Evaluatecriteriaforanalyzingdataaccessperformance.ApplyperformanceconsiderationstobinarylargeobjectBLOBmanipulation.OverviewWelldesigneddataaccesscodeanddataprocessingcommandsareessentialelementsforapplicationperformanceandscalability.Typically,thedatabaseisafocalpointforapplicationloadbecausethemajorityofapplicationrequestsrequiredatathatcomesfromadatabase.Thischapterprovidesprovenstrategiesfordesigningandimplementingdataaccesscodeforperformanceandscalability.HowtoUseThisChapterUsethischaptertoimprovetheimplementationofyourdataaccesscodeforperformanceandscalability.Togetthemostoutofthischapter,considerthefollowingJumptotopicsorreadbeginningtoend.Themainheadingsinthischapterhelpyoutoquicklyidentifyandthenlocatethetopicthatinterestsyou.Alternatively,youcanreadthechapterbeginningtoendtogainathoroughappreciationoftheissuesthataffectADO.NETperformance.Usethechecklist.UseChecklistADO.NETPerformanceintheChecklistssectionofthisguidetoquicklyviewandevaluatetheguidelinespresentedinthischapter.UsetheArchitecturesectionofthischaptertounderstandhowADO.NETworks.Byunderstandingthearchitecture,youcanmakebetterdesignandimplementationchoices.UnderstandcoreADO.NETcomponents,suchasdataproviderobjectsandtheDataSetobject.UsetheDesignConsiderationssectionofthischaptertounderstandthehighleveldecisionsthatwillaffectimplementationchoicesforADO.NETcode.Measureyourapplicationperformance.learnaboutthekeymetricsthatyoucanusetomeasureapplicationperformance.Youhavetomeasureapplicationperformancesothatyoucanidentifyandresolveperformanceissues.Testyourapplicationperformance.Testing.NETApplicationPerformancetolearnhowtoapplyperformancetestingtoyourapplication.Youhavetoapplyacoherenttestingprocessandanalyzetheresults.Tuneyourapplicationperformance.Tuning.NETApplicationPerformancetolearnhowtoresolveperformanceissuesthatyouidentifythroughtheuseoftuningmetrics.TuneSQLServer.ReadChapter14,ImprovingSQLServerPerformancetoensurethatyourMicrosoft®SQLServer™databaseisappropriatelyconfigured.ArchitectureADO.NETreliesondataproviderstoprovideaccesstotheunderlyingdatasource.Eachdataproviderexposesasetofobjectsthatyouusetomanageconnections,retrievedata,andupdatedata.ThecoreobjectsarethefollowingConnectionCommandDataReaderDataAdapterInaddition,ADO.NETprovidestheDataSetobject,whichprovidesadisconnectedcacheofdata.TheDataSetobjectdoesnotrequireaspecifictypeofdatasourceandisnottiedtotheunderlyingdatasourcethatthedatawasobtainedfrom.ThebasicADO.NETarchitectureisshowninFigure12.1.Figure12.1ADO.NETarchitectureThefollowinglistoutlinesthepurposeofeachofthemainADO.NETobjectsConnection.Thisobjectrepresentsaconnectiontoadatabase.Command.ThisobjectrepresentsanSQLstatementthatisrunwhileconnectedtoadatasource.ThisobjectcanbeastoredprocedureoradirectSQLstatement.DataReader.Thisobjectretrievesareadonly,forwardonlystreamofdatafromadatabase.TheDataReaderobjectisdesignedforconnectedscenariosandoffersbetterperformancethanreadingdataintoaDataSetobjectattheexpenseoffunctionality.FormoreinformationabouthowtouseDataReaderobjectsandDataSetobjects,seeDataSetvs.DataReaderlaterinthischapter.DataAdapter.ThisobjectchannelsdatatoandfromaDataSetobjectandtheunderlyingdatasource.TheDataAdapterobjectalsoprovidesenhancedbatchupdatefeaturesthatwerepreviouslyassociatedwiththeADORecordsetobject.DataSet.TheDataSetobjectrepresentsadisconnected,cachedsetofdata.TheDataSetisindependentoftheproviderandisnottiedtotheunderlyingdatasourcethatmighthavebeenusedtopopulateit.DataSetcaneasilybepassedfromcomponenttocomponentthroughthevariouslayersofanapplication,anditcanbeserializedasXML.YoushouldbeawareofthewayaDataSetisinternallyconstructedbecausetheDataSetcontainsapotentiallylargenumberofinternalobjects.ThismeansthatalargenumberofmemoryallocationsarerequiredtoconstructatypicalDataSet.ADataSetconsistsofoneormoreDataTableobjectstogetherwithDataRelationobjectsthatmaintaintablerelationshipinformation.EachDataTablecontainsDataRowobjectsandDataColumnobjects.ConstraintobjectsareusedtorepresentaconstraintthatcanbeenforcedononeormoreDataColumnobjects.NoteYoucanalsousetypeddatasetsthatderivefromthebasicDataSetclass.Typeddatasetsprovidebenefitsatbuildtimeandatruntime.Formoreinformation,seeTypedDataSetslaterinthischapter.DataView.AlthoughtheDataViewobjectisnotshowninFigure12.1,youcanuseaDataViewtosortandfilterdatainaDataTable.Thiscapabilityisoftenusedfordatabinding.AbstractingDataAccessADO.NETisdesignedaroundasetofgenericinterfacesthatabstracttheunderlyingdataprocessingfunctionality.Youcanusetheseinterfacesdirectlytoabstractyourdataaccesslayersothatyoucanminimizetheimpactofchangingthetypeofdatasourcethatyouuse.Abstractingdataaccessisextremelyhelpfulwhenyouaredesigningsystemswhereyourcustomerchoosesthedatabaseserver.ThecoreinterfacesprovidedbyADO.NETarefoundintheSystem.DatanamespaceIDbConnection.Thisisaninterfaceformanagingdatabaseconnections.IDbCommand.ThisisaninterfaceforrunningSQLcommands.IDbTransaction.Thisisaninterfaceformanagingtransactions.IDataReader.Thisisaninterfaceforreadingdatareturnedbyacommand.IDataAdapter.Thisisaninterfaceforchannelingdatatoandfromdatasets.Thevariousproviderobjects,suchasSqlConnectionandOleDbConnection,implementthesegenericADO.NETdataaccessinterfaces.Ifyoudecidetoprogramagainstthegenericinterfaces,beawareofthefollowingissuesThereissomesmallcostassociatedwithavirtualcallthroughaninterface.Certainexpandedfunctionalityislostwhenyouusethegenericinterfaces.Forexample,theExecuteXmlReadermethodisimplementedbytheSqlCommandobjectbutnotbytheIDbCommandinterface.Thereisnogenericbaseexceptiontype,soyoumustcatchproviderspecificexceptiontypes,suchasSqlException,OleDbException,orOdbcException.Whenyouusethegenericinterfaces,youcannottakeadvantageofdatabasespecifictypesthataredefinedforthemanagedprovidersforexample,youcannottakeadvantageofSqlDbTypeinSqlClientandOraclespecifictypesintheOracleprovider.Usingspecificdatabasetypesishelpfulfortypecheckingandparameterbinding.PerformanceandScalabilityIssues

注意事项

本文(外文翻译---改进ADO.NET性能.doc)为本站会员(英文资料库)主动上传,人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知人人文库网([email protected]),我们立即给予删除!

温馨提示:如果因为网速或其他原因下载失败请重新下载,重复下载不扣分。

copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5