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wultiple glendr upp ort for gonventionl htse wngement ystems I wihel hF o o P ihrd F no dgrss WPEHU perury PVD IWWP estrt e prop ose solution to the prolem of supp orting timeEstmp ttriute domin in onventionl reltionl dtse mngement systemsF sn ontrst to existing prop oslsD whih ssume tht single interprettion of time is suient for ll users nd pplitionsD we develop generl solution tht supp orts multiple interprettions of timeF he min onept underlying this prop osl is tht the universl sp ets of time re seprted from the user dep endent sp etsD t oth the query lnguge nd the rhiteturl levelsF he user dep endent sp ets re enpsulted in lendrs nd lendri systemsD eh of whih re extendile y lo l site p ersonnelF sn this wyDtheville time supp ort n e ustomized to lo l requirementsF e riey desri e mo ditions to vP tht supp ort multiple lendrs nd lendri systemsF hese mo ditions redue the omplexityof the lnguge while simultneously inresing its expressive p owerF pinllyD we desri e set of to ols tht id in the genertion of lendrs nd lendri systemsF his work n e viewed s limited ut prtil pplition of reserh into extensile dtse mngement systemsF I heprtment of gomputer iene niversity of erizon usonD e VSUPI soodsFrizonFedu P heprtment of gomputer iene niversity of erizon usonD e VSUPI rtsdsFrizonFedu wultiple glendr upp ort for gonventionl htse wngement ystems I gontents I sntro dution I P hysil imeD glendrsD nd glendri ystems I PFI hysil ime XX XXX XXX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X I PFP glendrs X XXX XXX XXX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X P PFQ glendri ystems XX XXX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X Q PFR ummry X XXX XXX XXX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X R Q v vnguge wo diti ons R QFI ht yp es XXX XXX XXX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X R QFP glendri ystem nd rop erty eletion XXX XXX XXX XXX XX XXX XXX X T QFPFI glendri ystem p eition XX XXX XXX XXX XXX XX XXX XXX X T QFPFP rop erty p eition XX XX XXX XXX XXX XXX XXX XX XXX XXX X U QFQ fuiltEin puntions XX XXX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X V QFR erithmeti ixpressions XX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X V QFS gomprison ixpressions XX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X V QFT eggregte puntions X XXX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X W QFU ummry X XXX XXX XXX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X W R ystem erhiteture W RFI yverview XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX W RFP imeEstmp eh upp ort X XXX XX XXX XXX XXX XXX XXX XX XXX XXX X II RFQ niform glendri upp ort XXX XX XXX XXX XXX XXX XXX XX XXX XXX X II RFR uery ro essing usystem XX XX XXX XXX XXX XXX XXX XX XXX XXX X IP RFRFI emnti enlysis X XXX XX XXX XXX XXX XXX XXX XX XXX XXX X IQ RFRFP unEtime ystem XX XXX XX XXX XXX XXX XXX XXX XX XXX XXX X IQ RFS glendri ystem ht trutures X XXX XXX XXX XXX XXX XX XXX XXX X IR RFT glendrs XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX IR RFU qenerting glendrs nd glendri ystems X XXX XXX XXX XX XXX XXX X IU RFV erhiteturl smplitions of ixtensiility XXX XXX XXX XXX XX XXX XXX X IW S elted ork IW T gonlusions nd puture ork PI U eknowledgements PP V filiogrphy PP i I sntro dution he vgunit workshop on future reserh in dtse systems identied the need for dtse mngement systems to supp ort time il ershtz et lF IWWHF he workshop rep ort notes tht no onsensus exists in supp ort of ny prtiulr temp orl mo delY the very nture of time implies dierent interprettions dep endin g on the user9s p ersp etiveF sn this pp erD we prop ose solution to the prolem of supp orting timeEstmp ttriute domin in onventionl reltionl dtse mngement systems @hfwsAF yur motivtion is tht timeD p erhps more thn ny other dt dominD is su jet to userEinterprettion|the hfw must e ple of ommo dting the interprettion of time pplil e to user or siteF gonventionl reltionl dtse mngement systems do not ddress this prolem t llY insted they imp ose single interprettion of time t oth the query lnguge nd rhiteturl levelsF e present generl solution thtD in eetD interntionlizes the timeEstmp ttriute domin provided y hfwF his work is lso pplile to time representtion in temp orl dtse mngement systems no dgrss 8 ehn IWVTF he fo us of this pp er is on rhiteturl requirements for time vlue supp ortD though we lso ddress query lnguge issuesF e present summry of mo ditions to v welton IWWHto supp ort temp orl dtD nd then develop n underlyin g system rhitetureF he min onept underlying the design is the seprtion of the universl sp ets of time from those tht re user dep endentF he supp ort for these sp ets of time is prtitioned t oth the query lnguge nd the rhiteturl levelsF his seprtion llows ustomiztion of userEdep ende nt time sp ets y lo l site p ersonnelF he prop osl employs limited notion of extensiilityF erhiteturl supp ort is provided for ddition nd mo dition of the dtse mngement system omp onents tht imp ose prtiulr interprettion on temp orl vluesF e prop ose limitedD ut prtilD pplition of the tehniques prop osed for extensile dtse mngement systems ftory et lF IWVVD grey 8 rs IWWHD grey et lF IWVTD rs et lF IWWHD tonerker et lF IWWHF yur pproh is relted to tht of extensile systems supp orting strt dt typ es @ehsAF roweverD we elieve tht ehs lone re indequte for the temp orl extensions develop ed hereD nd we rgue why in etion SF he pp er is orgnized s followsF etion P disusses generl strtions used to deE sri e time nd its use in so ietyD motivting the si dt mo del we prop oseF etion Q riey desri es v onstruts supp orting the onepts of etion PF he primry fo us of this pp erD system rhiteture supp orting the prop osed lnguge feturesD is desri ed in etion RF he nl two setions disuss res of relted reserhD summrize the ontriutions of this pp erD nd identify res of future reserhF P hysil imeD glendrsD nd glendri ystems his setion desri es the si mo del of time we prop oseF e rst exmine how time is represented internlly within the hfwD nd then intro due the onepts of lendrs nd lendri systemsF PFI hysil ime e ssume the ontinuous timeEline is quntized into hronons of xed durtionD nd the grnulrity of time vlue t the query lnguge level is extly one hrononF he set of I hronons form niteD linerD nd totllyEordered set of time vlues with dened identity reltionF sn physil reltionD time vlues re represented y timeEstmpsDnumerivlues repreE senting hrononsF yp ertions on time vlues re p erformed y exeuting nlogous op ertions on timeEstmps orresp onding to those temp orl vluesF he ext semntis of this internl representtion re desri ed elsewhere hyreson 8no dgrss IWWPD ut the detils re not relevnt hereF e note tht timeEstmpsD while hving preise semntis tied to physil lo ksD re indep end ent of n interprettion implied y user p ersp etiveF uh n interprettionD of whih there ould e severlD re provided y lendrsD whih we now desri eF PFP glendrs e lendr is humn strtion of the physil timeElineF yne lendr fmilir to mny is the qregorin lendrD sed on the rottion of the irth on its xis nd its revolution round the unF ome western ultures hve used the qregorin lendr sine the lte ITth entury to mesure the pssge of timeF es nother exmpleD sslmis generlly use lunr lendrD sed on the mount of time required for the wo on to rotte round the irthF he qregorin nd lunr lendrs re exmples of dily nd monthly lendrsD utD in generlD lendr n mesure time using ny wellEdened time unitF por exmpleD n employee time rd n e regrded s lendr whih mesures time in eight hour inrements nd is only dened for ve dys of eh weekF e note tht mny dierent lendrs existD nd tht no lendr is inherently etter4 thn notherY the vlue of prtiulr lendr is wholly determined y the p opultion tht uses itF le I lists severl exmple lendrsF hesription glendr evised universl o ordinted time gP gommon western solr with months qregorin gommon estern lunr vunr estern solr with yers nd dys tulin PTH dy yles wesoEmerin er onsists of semesters edemi pinnil yer egins t xew er gommon pisl pinnil yer strts in pll edemi pisl pinnil yer strts in yto er pederl pisl V hour dys nd S dy weeks ime rd PR hour dy divided into three shifts of V hours QEshift ork hy ime sed on rdiotive dey gr onEIR ime sed on geologi pro esses qeologi le IX gommon glendrs e emphsize tht the usge of lendr dep ends on the ulturlD leglD nd even usiE ness orienttion of the userF por exmpleD usiness enterprises generlly p erform ounting reltive to some sl yerF roweverD the denition of sl yer vries dep ending on the enterpriseF niversities my hve their sl lendr oinide with the demi yer in orE der to simplify ountingF yther institutions use the more ommon hlfEyerly or qurterly denitions of sl yerF P glendrs hvetwo typ es of hrteristisD intrinsi hrteristis tht dene the uniE versl qulities of the lendrD nd extrinsi hrteristis tht dene the userEdep ende nt or vrying qulities of the lendrF he intrinsi hrteristis of lendr dene the intrinsi semntis of the lendr or omp onents tht dep end diretly on suh semntisF por exmpleD the durtion of time units @eFgFD weekD monthAnd their interreltionships re intrinsi omp onents of lendrF puntions p erforming lendr dened omputtions re lso intrinsiF por exmpleD in the qregorin lendr one ould onstrut eld extrtion funtionD month nme ofD tht returns the nme of the month of given dteF imilrlyD funtion hrvest moon dte ould e used to ompute the dte of the hrvest mo on in given yerF he extrinsi hrteristisD termed propertiesD of lendr vry dep endi ng on the orienttion of the userD s disussed oveF e typil lendr prop erty is the lnguge in whih time vlues re expressedF por exmpleD in the qregorin lendr inglish is used to express dtes in the nited