iwuhlelo lokuphathwa kolwazi olugciniwe oluhambisana ne-ACID, oluqukethwe kumtapo wolwazi omncane obhalwe ngo-C
Abathuthukisi bephrojekthi I-SQLite isiqalile ukuhlola i-HCtree backend yokuhlola esekela ukukhiya kwezinga lomugqa futhi inikeze izinga eliphezulu lokufana ekucubunguleni imibuzo.
Mayelana ne-backend entsha abasebenza kuyo, kuyashiwo ukuthi lokhu ihlose ukuthuthukisa ukusebenza kahle kokusebenzisa i-SQLite ezinhlelweni zeseva yeklayenti Kufanele bacubungule inani elikhulu lezicelo zokubhala ngesikhathi esisodwa kusizindalwazi.
I-Las Izakhiwo ze-b-tree ezisetshenziswe ekuqaleni ku-SQLite ukugcina idatha Aziklanyelwe lolu hlobo lomthwalo., ekhawulela i-SQLite ekubhaleni ukusakaza okukodwa kuphela. Njengokuhlola, abathuthukisi baqale ukwenza esinye isixazululo esisebenzisa izakhiwo ze-HCtree ukuze sigcinwe, esilungele kangcono imisebenzi yokubhala ehambisanayo.
Iphrojekthi ye-HC-tree (hctree) iwumzamo wokuthuthukisa isizindalwazi esisha esithuthukisa i-SQLite evamile ngale ndlela elandelayo:
Ukuvumelana okuthuthukisiwe: Ukusebenzisa isandiso sokuqala ngesikhathi esisodwa kushintsha lokhu ukuze sisetshenziswe ngesikhathi esifanayo kusetshenziswa ukukhiya okunethemba ezingeni lekhasi. Lokhu kuthuthukisa ukuhambisana kwezimali ngandlela thile, kodwa ukukhiya ezingeni lekhasi kungathola ukungqubuzana phakathi kokwenziwayo okuzimele okunengqondo, futhi imisebenzi ye-COMMIT isadinga ukuhlelwa.
Usekelo lokuphindaphinda: I-Stock SQLite isekela i- isandiso seseshini, okuvumela okuqukethwe komsebenzi ozibophezele ukuthi kuhlelwe ukuze kudluliselwe futhi kufakwe kusizindalwazi sesibili. I-Hctree ihlanganisa lokhu kusizindalwazi esisemuva futhi yengeza usekelo lokusebenzisa lezo ntengiselwano kuzigcinilwazi zabalandeli ekucushweni komholi nabalandeli. Kulokhu, ukuthengiselana okutholwe kusizindalwazi esiholayo kungasetshenziswa ngokushesha nangokuvumelana okukhulu kunalezo ezisetshenziswe ekuqaleni kusizindalwazi esiholayo, ngoba akukho. ukuqinisekiswa kokwenziwayo.
Ukuqedwa komkhawulo kasayizi wesizindalwazi: I-Stock SQLite isebenzisa izinombolo zamakhasi angama-32-bit. Kusetshenziswa usayizi wekhasi ozenzakalelayo ongu-4 KiB, lokhu kuholela kusayizi omkhulu wesizindalwazi ongu-2^44 bytes noma 16 TiB.
Ukusingatha imisebenzi eminingana ngesikhathi esisodwa, Amalogi e-HCtree asebenzisa indlela yokuhlukanisa okwenziwayo esebenzisa izikhiya zeleveli yekhasi, efana ne-MVCC (ukulawulwa kokuqukethwe kwezinguqulo eziningi), kodwa isebenzisa izilawuli zokwenziwayo ezisekelwe kububanzi obuyinhloko nobubanzi bokhiye esikhundleni samasethi ekhasi.
Imisebenzi yokufunda nokubhala yenziwa ngokuhlobene nesifinyezo sesizindalwazi, izinguquko ezibonakala kusizindalwazi esiyinhloko kuphela ngemva kokuba umsebenzi usuqedile.
Amaklayenti angasebenzisa imisebenzi emithathu ukuvula ukuthengiselana:
- «QALA«: Okwenziwayo akunaki idatha yokufinyelela yamanye amakhasimende. Uma imisebenzi yokubhala yenziwa ngaphakathi kokuthengiselana, ukuthengiselana kungenziwa kuphela uma bekungekho okunye ukubhala kusizindalwazi ngesikhathi sokwenziwa kwayo.
«QALA NGESINYE«: Imisebenzi iqoqa ulwazi mayelana nokufinyelela kwamanye amaklayenti. Uma imisebenzi yokubhala yenziwa ngaphakathi kokwenziwe, umsebenzi ungenziwa uma okunye ukuthengiselana kwenziwe kusizindalwazi kusukela kwadalwa isifinyezo.
«QALA OKUKHETHEKILE«: ngemva kokuvula umsebenzi, vimba ukusebenza kokunye ukuthengiselana kuze kuqedwe.
I-HCtree isekela ukuphindaphinda kwe-master-slave, okukuvumela ukuthi udlulisele okwenziwayo kwenye isizindalwazi futhi ugcine imininingwane egciniwe yesibili ivunyelaniswa nesizindalwazi esiyinhloko.
I-HCtree iphinde isuse umkhawulo kasayizi wesizindalwazi: esikhundleni sezihlonzi zekhasi ledatha lamabhithi angu-32, i-HCtree isebenzisa izihlonzi ezingamabhithi angu-48, okwandisa umkhawulo kasayizi wesizindalwazi usuka kuma-tebibytes angu-16 ukuya ku-exbibyte o-1 (ama-tebibytes ayizigidi).
Ukusebenza kwe-SQLite nge-HCtree backend kulindeleke ukuthi okungenani kube kuhle njenge-backend yakudala yochungechunge olulodwa. Amaklayenti e-SQLite anokwesekwa kwe-HCtree azokwazi ukufinyelela kokubili isizindalwazi se-HC-tree kanye nesizindalwazi sefa le-SQLite.
Umthombo: https://sqlite.org/