1、南開大學碩士學位論文從網狀到關系數據庫映射的研究姓名：蔡洪基申請學位級別：碩士專業(yè)：軟件工程指導教師：李旭東20070401AbstractAbstractTodayrelationaldatabasesystemsarethemostpopulardatabasesystemsbecausetheirDMLsaremoreuserfriendlyandpowerfulthantheDMLsofotherdatabasesystemsA

2、lthoughthemajorityofnewdatabasesystemsarerelational，therearestillasubstantialnumberofnetworkdatabasesystemsinuseTherefore。animportantquestionishowtograduallyconvertfromtheoldnetworktothenCWrelationaltechnologyTherearetwo

3、kindsofmigrationsolutionsOneCanredesignthedatabaseschemaonthenewrelationalDBMS，writeasetofroutinesformappingthedatafromthenetworkdatabasetotherelationaldatabase，rewritealltheapplicationprogramstunOlltherelationaldatabase

4、，andthrowawaythenetworkdatabaseanditsapplicationprograms；onecanapplyoneofthewell—knownandgeneralalgorithmsformappinganetworkdatabaseintoarelationaldatabase，rewritealltheapplicationprogramstunontherelationaldatabase，andth

5、rowawaythenetworkdatabaseanditsapplicationprogramsThesetwosolutionsmightbeworkableinthetheorypointofviewbuttherewritingworkofalltheapplicationwouldbelongjourneyfullofdangerandrisksandmightbecosttoomuchtoexecuteThesystema

6、fterthemigrationwillbecomeunstablethenbeforebecauseofthelackingoftimefortestThesearethemajorreasonswhichpreventthelargesystembaseonnetworkDBMSmigratingtothenewrelationDBMSThispaperwillintroduceat11irdmigrationsolutionwhi