基于可擴(kuò)展置標(biāo)語(yǔ)言的通用數(shù)據(jù)訪(fǎng)問(wèn)模型研究.pdf

1、華中科技大學(xué)碩士學(xué)位論文基于可擴(kuò)展置標(biāo)語(yǔ)言的通用數(shù)據(jù)訪(fǎng)問(wèn)模型研究姓名：楊兵申請(qǐng)學(xué)位級(jí)別：碩士專(zhuān)業(yè)：計(jì)算機(jī)應(yīng)用技術(shù)指導(dǎo)教師：宋善德20040509華中科技大學(xué)碩士學(xué)位論文AbstractNETheterogeneousdataaccessingstrategyhasrenderedaverygoodsolutiontotheintegrationofseveraldistributed，heterogeneousandautonomous

2、databasesButwiththerapiddevelopmentofthenetworks，heterogeneousdataaccessinghastomanagenotonlythestructureddataintraditionaldatabasesbutfilesystemaswellTheintegrationofsemistmctureddataandnostructureddatainfilesystemisane

3、wchallengetoheterogeneousdataaccessingstrategiesHowtoobtainandintegratedatabasesystemandfilesystemdatainNETandforwardanintegratedviewtotheusershasbecomeaveryimportantissueinthisresearchareaAfteranalyzingtheresearchachiev

4、ementsinstructureddata，semistructureddatanostructureddataandXML，weputforwardanapproachtointegratedatafromheterogeneousdatasourcesAimedatthecharacteristicsofXML，thisapproachusesXMLasmedialdatamodelfortheintegrationofheter

5、ogeneousdataSOUrCesandhowtochangestructureddata，semistructureddataandnostructureddatatoXML’smodel，solvingthesemanticandfunctionaldifferencesbetweenthemthroughlocalagentsThereisalsoaneedtoextendqueryoptimizationarchitectu

6、reintheintegrationofheterogeneousdatasourcesbecauseoftheintegrationoffilesystem。Becauseofthebigdifferencebasedonthequeryabilityofeachdatasources，andallkingsofdatasourcescanturntoXML’smodel，westudythequeryoptimizationofXM

7、Lputforwardanapproachtealizethequeryoptimizationbasedonindex，andmanagethequeryrewritingafterqueryWedesignedandimplementedaXML—basedgeneraldataaccessingmodelwithNETonabovemethodsTheintegrationincludingsemistructureddataan

8、dnostructureddataisintroduced，whichcanextractdatafromHTMLWebpagesandgeneratealocalschema，thereforeprovidestransparentinteroperabilityamongfilesystemdatasourcesandexistingdatabasemanagementsystemssuchasOracle8andSybaseKey