yinkqubo yolawulo lwesiseko sedatha ehambelana ne-ACID, equlethwe kwithala leencwadi elincinci elibhalwe kuC
Abaphuhlisi beprojekthi I-SQLite iqalile ukuvavanya i-HCtree backend yovavanyo exhasa ukutshixelwa komgangatho werowu kwaye ibonelele ngenqanaba eliphezulu lokunxulunyaniswa nokusetyenzwa kwemibuzo.
Ngokumalunga ne-backend entsha abasebenza kuyo, kukhankanyiwe ukuba oku ijolise ekuphuculeni ukusebenza kakuhle kokusebenzisa iSQLite kwiinkqubo zomncedisi womxhasi Kufuneka baqhubele phambili inani elikhulu lezicelo zokubhala ngaxeshanye kwiziko ledatha.
Las Izakhiwo ze-b-tree ezazisetyenziswa ekuqaleni kwiSQLite ukugcina idatha Azenzelwanga ngolu hlobo lomthwalo., enqanda iSQLite ekubhaleni kumsinga omnye kuphela. Njengovavanyo, abaphuhlisi baqala ukuphuhlisa esinye isisombululo esisebenzisa izakhiwo zeHCtree zokugcinwa, ezifanelekileyo ngakumbi ekusebenzeni ngokuhambelana nokubhala.
Iprojekthi yeHC-tree (hctree) ilinge lokuphuhlisa i-backend entsha yedatha ephucula kwiSQLite eqhelekileyo ngolu hlobo lulandelayo:
Uphuculo lwesivumelwano: Ukusebenzisa ulwandiso lwesiqalo-ngaxeshanye lutshintsha oku ukuze luphunyezwe ngaxeshanye kusetyenziswa ukutshixa okunethemba kwinqanaba lephepha. Oku kuphucula i-concurrency ngandlel 'ithile, kodwa ukutshixa kwinqanaba lekhasi kunokubona ukungquzulana phakathi kwentengiselwano ezimeleyo ngokwengqiqo, kwaye imisebenzi ye-COMMIT isafuna ukwenziwa uthotho.
Inkxaso yokuphindaphinda: Stock SQLite ixhasa i ulwandiso lweseshoni, evumela umxholo wentengiselwano ezinikeleyo ukuba ilandelelwe ukuhanjiswa kunye nesicelo kwisiseko sedatha yesibini. I-Hctree idibanisa oku kwi-backend yesiseko sedatha kwaye yongeza inkxaso yokusebenzisa utshintshiselwano olunjalo kuluhlu lwabalandeli kuqwalaselo lwabalandeli benkokeli. Kule meko, iintengiselwano ezifunyenwe kwisiseko sedatha esikhokelayo zinokusetyenziswa ngokukhawuleza kwaye ngokuhambelana okukhulu kunezo zisetyenziswe ekuqaleni kwisiseko sedatha esikhokelayo, kuba akukho. ukuqinisekiswa kwentengiselwano.
Ukupheliswa komlinganiselo wobungakanani bedatabase: Stock SQLite isebenzisa 32-bit amanani amaphepha. Ukusebenzisa ubungakanani bephepha obungagqibekanga be-4 KB, oku kukhokelela kubungakanani besiseko sesiseko esikhulu se 2^44 bytes okanye 16 TiB.
Ukuphatha imisebenzi emininzi ngexesha elinye, Izigodo zeHCtree zisebenzisa indlela yokwahlula intengiselwano esebenzisa izitshixo zenqanaba lephepha, elifana neMVCC (iinguqulelo ezininzi zolawulo lwesiqulatho), kodwa isebenzisa ulawulo lwentengiselwano olusekwe kuluhlu oluphambili kunye noluhlu oluphambili endaweni yeeseti zephepha.
Imisebenzi yokufunda nokubhala iyenziwa ngokunxulumene ne-snapshot yedathabheyisi, utshintsho olo lubonakala kwisiseko sedatha kuphela emva kokuba intengiselwano igqityiwe.
Abathengi banokusebenzisa imisebenzi emithathu ukuvula intengiselwano:
- «QALA«: Iintengiselwano azithatheli ngqalelo idatha yokufikelela yabanye abathengi. Ukuba imisebenzi yokubhala yenziwa ngaphakathi kwentengiselwano, intengiselwano inokwenziwa kuphela ukuba bekungekho eminye imisebenzi yokubhala kwisiseko sedatha ngexesha lokwenziwa kwayo.
«QALA NGEXESHA«: Iintengiselwano ziqokelela ulwazi malunga nokufikelela kwabanye abathengi. Ukuba imisebenzi yokubhala yenziwa ngaphakathi kwentengiselwano, intengiselwano inokwenziwa ukuba ezinye iintengiselwano zibopheleleke kwisiseko sedatha ukusukela oko kwenziwa umfanekiso okhawulezayo.
«QALA NGOKUKHETHAYO«: emva kokuvula intengiselwano, ivimba imisebenzi yezinye iintengiselwano ide igqitywe.
I-HCtree ixhasa ukuphindaphinda kwe-master-slave, ekuvumela ukuba udlulisele ukuthengiselana kwenye i-database kwaye ugcine i-database ye-secondary sync kunye nesiseko sesiseko.
I-HCtree iphinda isuse umda wesayizi wesiseko sedatha: endaweni yezazisi zephepha ledatha ye-32-bit, i-HCtree isebenzisa i-identifiers ye-48-bit, eyandisa ubungakanani bedatha egciniweyo ukusuka kwi-16 tebibytes ukuya kwi-exbibyte e-1 (i-tebibytes ezigidi).
Ukusebenza kwe-SQLite kunye ne-HCtree backend kulindeleke ukuba ibe yinto efanelekileyo njenge-classical-threaded backend. Abathengi beSQLite abanenkxaso yeHCtree baya kukwazi ukufikelela kuluhlu lweenkcukacha ze-HC-tree kunye nedatha ye-SQLite yelifa.
Umthombo: https://sqlite.org/