外文翻译---改进ADO.NET性能.doc
收藏
编号:97921
类型:共享资源
大小:101.50KB
格式:DOC
上传时间:2013-11-17
上传人:上***
认证信息
个人认证
高**(实名认证)
江苏
IP属地:江苏
6
积分
- 关 键 词:
-
教育专区
外文翻译
精品文档
外文翻译
- 资源描述:
-
附录1.英文资料ImprovingADO.NETPerformanceImproving.NETApplicationperformanceandscalabilitySummary:Thischapterprovidesprovenstrategiestohelpyoudesignanddevelopscalabledataaccesssolutions.Topicscoveredincludedifferenttechniquestopassdataacrossapplicationlayers,managingthedatabaseconnectionpool,optimizingstoredprocedurecalls,reducingdatasetserializationcost,techniquesforpagingthroughlargeresultsets,managingtransactions,handlingBLOBS,andmuchmore.ObjectivesOptimizeyourdataaccessdesign.ChoosebetweenDataSetsandDataReaders.Runefficientdatabasecommands.Passdatabetweenlayersefficiently.Performefficienttransactions.Optimizeconnectionmanagement.Evaluatethecostofpagingthroughrecords.Evaluatecriteriaforanalyzingdataaccessperformance.Applyperformanceconsiderationstobinarylargeobject(BLOB)manipulation.OverviewWell-designeddataaccesscodeanddataprocessingcommandsareessentialelementsforapplicationperformanceandscalability.Typically,thedatabaseisafocalpointforapplicationloadbecausethemajorityofapplicationrequestsrequiredatathatcomesfromadatabase.Thischapterprovidesprovenstrategiesfordesigningandimplementingdataaccesscodeforperformanceandscalability.HowtoUseThisChapterUsethischaptertoimprovetheimplementationofyourdataaccesscodeforperformanceandscalability.Togetthemostoutofthischapter,considerthefollowing:Jumptotopicsorreadbeginningtoend.Themainheadingsinthischapterhelpyoutoquicklyidentifyandthenlocatethetopicthatinterestsyou.Alternatively,youcanreadthechapterbeginningtoendtogainathoroughappreciationoftheissuesthataffectADO.NETperformance.Usethechecklist.Use"Checklist:ADO.NETPerformance"inthe"Checklists"sectionofthisguidetoquicklyviewandevaluatetheguidelinespresentedinthischapter.Usethe"Architecture"sectionofthischaptertounderstandhowADO.NETworks.Byunderstandingthearchitecture,youcanmakebetterdesignandimplementationchoices.UnderstandcoreADO.NETcomponents,suchasdataproviderobjectsandtheDataSetobject.Usethe"DesignConsiderations"sectionofthischaptertounderstandthehigh-leveldecisionsthatwillaffectimplementationchoicesforADO.NETcode.Measureyourapplicationperformance.learnaboutthekeymetricsthatyoucanusetomeasureapplicationperformance.Youhavetomeasureapplicationperformancesothatyoucanidentifyandresolveperformanceissues.Testyourapplicationperformance."Testing.NETApplicationPerformance"tolearnhowtoapplyperformancetestingtoyourapplication.Youhavetoapplyacoherenttestingprocessandanalyzetheresults.Tuneyourapplicationperformance."Tuning.NETApplicationPerformance"tolearnhowtoresolveperformanceissuesthatyouidentifythroughtheuseoftuningmetrics.TuneSQLServer.ReadChapter14,"ImprovingSQLServerPerformance"toensurethatyourMicrosoft®SQLServer™databaseisappropriatelyconfigured.ArchitectureADO.NETreliesondataproviderstoprovideaccesstotheunderlyingdatasource.Eachdataproviderexposesasetofobjectsthatyouusetomanageconnections,retrievedata,andupdatedata.Thecoreobjectsarethefollowing:ConnectionCommandDataReaderDataAdapterInaddition,ADO.NETprovidestheDataSetobject,whichprovidesadisconnectedcacheofdata.TheDataSetobjectdoesnotrequireaspecifictypeofdatasourceandisnottiedtotheunderlyingdatasourcethatthedatawasobtainedfrom.ThebasicADO.NETarchitectureisshowninFigure12.1.Figure12.1:ADO.NETarchitectureThefollowinglistoutlinesthepurposeofeachofthemainADO.NETobjects:Connection.Thisobjectrepresentsaconnectiontoadatabase.Command.ThisobjectrepresentsanSQLstatementthatisrunwhileconnectedtoadatasource.ThisobjectcanbeastoredprocedureoradirectSQLstatement.DataReader.Thisobjectretrievesaread-only,forward-onlystreamofdatafromadatabase.TheDataReaderobjectisdesignedforconnectedscenariosandoffersbetterperformancethanreadingdataintoaDataSetobjectattheexpenseoffunctionality.FormoreinformationabouthowtouseDataReaderobjectsandDataSetobjects,see"DataSetvs.DataReader"laterinthischapter.DataAdapter.ThisobjectchannelsdatatoandfromaDataSetobjectandtheunderlyingdatasource.TheDataAdapterobjectalsoprovidesenhancedbatchupdatefeaturesthatwerepreviouslyassociatedwiththeADORecordsetobject.DataSet.TheDataSetobjectrepresentsadisconnected,cachedsetofdata.TheDataSetisindependentoftheproviderandisnottiedtotheunderlyingdatasourcethatmighthavebeenusedtopopulateit.DataSetcaneasilybepassedfromcomponenttocomponentthroughthevariouslayersofanapplication,anditcanbeserializedasXML.YoushouldbeawareofthewayaDataSetisinternallyconstructedbecausetheDataSetcontainsapotentiallylargenumberofinternalobjects.ThismeansthatalargenumberofmemoryallocationsarerequiredtoconstructatypicalDataSet.ADataSetconsistsofoneormoreDataTableobjectstogetherwithDataRelationobjectsthatmaintaintablerelationshipinformation.EachDataTablecontainsDataRowobjectsandDataColumnobjects.ConstraintobjectsareusedtorepresentaconstraintthatcanbeenforcedononeormoreDataColumnobjects.NoteYoucanalsousetypeddatasetsthatderivefromthebasicDataSetclass.Typeddatasetsprovidebenefitsatbuildtimeandatruntime.Formoreinformation,see"TypedDataSets"laterinthischapter.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,soyoumustcatchprovider-specificexceptiontypes,suchasSqlException,OleDbException,orOdbcException.Whenyouusethegenericinterfaces,youcannottakeadvantageofdatabase-specifictypesthataredefinedforthemanagedproviders;forexample,youcannottakeadvantageofSqlDbTypeinSqlClientandOracle-specifictypesintheOracleprovider.Usingspecificdatabasetypesishelpfulfortypecheckingandparameterbinding.PerformanceandScalabilityIssues
- 内容简介:
-
-
- 温馨提示:
1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 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,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。