acquisitions and acquisitions et bibliographic semces services bibliographiques

《acquisitions and acquisitions et bibliographic semces services bibliographiques》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、THEUNTVERSITYOFCALGARYFlexileDataSharinginaGroupwareToolkitbyTheodore0'GradyATHESISSUBMLTTEDTOTHEFACULTYOFGRADUATESTUDIESINPARTIALFWLFILLMENTOFTHEREQUIREMENTSFORTHEDEGREEOFMASTEROFSCIENCEDEPARTMENTOFCOMPUTERSCIENCECALGARY,ALBERTANOVEMBER,1996@Theodore0'Grady1996NationalLibraryBibl

2、ioth4quenationaleduCanadaAcquisitionsandAcquisitionsetBibliographicSeMcesservicesbibliographiquesTheauthorhasgrantedanon-L'auteuraaccord6melicencenonexclusivelicenceallowingtheexclusivepermettantalaNationalLi'braryofCanadatoBiblioth¥ationaleduCanadadereproduce,loan,distn'buteor

3、sellrepro&ife,*,distn'bueroucopiesofhis/herthesisbyanymeansv&dredescopiesdesathkdeandinanyformorformat,makingthisthesisavailabletointerestedfomequecesoitpourmettredespersons.exemplairesdecettethesealadispositiondespersonnesmt6ressks.TheauthorretainsownershipoftheL'auteurconservela

4、propriet6ducopyrightinhis/herthesis.Neitherdroitd'auteurquiproegesaWse.Nithethesisnorsubstantialexbractslathksenidesactraitssubstantiehdefiomitmaybeprintedorotherwisecelle-cinedoivent&reimprimCsoureproducedwiththeauthor'sautrementreproduitssanssonpermission.AbstractSynchronousgrou

5、pwareapplicationsletuserscollaborateoverdistancethroughtheircomputers.Sincetheseapplicationsaredifficulttobuild,groupwaretoolkitshavebeenconstructedtohelpdeveloperswiththeirtasks.Someofthebuildingblockssuppliedbythesetoolkitsareasetofabstractionsforsharingdatabetweensites.Yetdiffe

6、renttoolkitsusedifferentstrategiestosharethedata:somereplicatethedataatallsites,whileothersstoreitatacentralsite.Thecorrectchoiceofdatasharingstrategyisnotobvious,asdifferentstrategiesaffatdataconsistencyaswellastheperformanceofapplicationsbuiltusingthetoolkit.Wearguethatdatashari

7、ngshouldbeflexibleandthatthedevelopershouldbeableconnolthedatasharingbyselectingfromdefaultstrategiesorcreatingnewonestomeettherequirementsoftheirapplication.Weuseatechniquecalledopenimplementationstoprovidethiscontrol.WehavebuiltaprototypegroupwaretookitcalledGENthatdemonstratest

8、hefeasibilityofflexibledatasharin