简介：CyberSpacefirstappearedinthesciencefiction,“Neuromancer”byW.Gibson(1984),thistermwasappliedfordescribingthedesperatevisionofthenearfuture,urbandecay,andneuralimplants.Recently,itisperceivedasawordreferringtoanentirelynewuniverseandthespacevirtuallyexistingwithintheworldwidecomputerInternet.　　BecauseCyberSpaceisanewworduptonow,thereisnotadefiniteconceptionaboutityet.Butwecanunderstanditasfollows:CyberSpaceisavirtualspacewhosedatainformationisstoredinthecomputerInternet.CreatinganyvirtualspacedependsontheelectronicaldataintheInternet.ThoughitislessthanacoupleofdecadessinceCyberSpacewasbroughtforward,ithadgrownatsucharemarkablespeedthatithadexpandedtothewidestcomputernetintheworld——Internet.Nowitsincrementstillmaintainsatthedoublerate　eachyear,anditisexpectedthattheCyberSpacewillbringanewparadigmofnetworksocietyforthenextcentury.　CyberSpacehasspecialspatialcharacteristics.Thephysicaldistanceisnotvalidinthisspace,sowemustuseanewapproachtodescribethedistance.Therearethreemethods.Oneisvaliddistancethatisafunctionaldistance,asthedistancearedescribedbytimeorcost.Thesecondisapsychologicaldistance.Namely,itisasubjectivemeasurementthatpeopleapperceivedistanceastheyareawayfromtheobject.Thethirdisaholisticdistancewhereeachchainhasitsunit.Ontheotherhand,mostCyberSpacedonottakeaccountofthegravity.Infact,thebearing,magnitudeortimeconsequenceofthegravitycanbedefinedatrandomandeasilymodified,however,theunitlengthanddirectionofthe3DvectorchangewiththedifferentpositionsinCyberSpace.Inthissense,thescaleorshapeofasinglebuildingandstreetarenotrestrictedbythespatialcondition.Theonlyfactormaintainingthespatialshapeistopologyreplacingtheorigingravity,systemtime,colorsetandspatialdimensionsetupwiththeownpsychologicals

简介：AnOracle8i-basedap-proachisproposedtomanagetheinte-grateddatabasesoflargeCyberCity.Thisapproachconsistsofthreeisdesignedtoacceleratespatialretrieving,inwhichtheboundingboxesoflocalregionshavenointersectionandallleafnodesoftheR+-tree(geome-tryrecords)havenorepetition;rithmsareadoptedtocompressthedigitalelevationmodels,3Dvectormodelsandimages,suchasLZ77losslesscompressionalgorithmforcompressionofvectordataandJPEGcompressionalgorithmsfortextureim-Oracle8idatabase,aCyberCityGISspatialdatabaseengine(SDE)isdesigned.OnthebasisofthisSDEpro-totypeacasestudyisdone.