SQLite project developers tau pib sim qhov kev sim HCtree backend uas txhawb nqa kab-theem xauv thiab muab qib siab ntawm kev sib luag thaum ua cov lus nug. Lub backend tshiab yog tsom rau kev txhim kho kev ua tau zoo ntawm kev siv SQLite hauv cov neeg siv-server systems uas yuav tsum tau ua cov txheej txheem ntau ib txhij sau thov rau cov ntaub ntawv.
Cov qauv b-ntoo ib txwm siv hauv SQLite los khaws cov ntaub ntawv tsis yog tsim los rau hom kev thauj khoom no, uas txwv SQLite sau rau ib qho xov nkaus xwb. Raws li kev sim, cov neeg tsim khoom tau pib tsim ib qho kev daws teeb meem uas siv HC-ntoo cov qauv rau kev khaws cia, uas tsim nyog rau kev ua haujlwm sib luag.
Txhawm rau tso cai rau ntau qhov haujlwm ua haujlwm ib txhij, HCtree cov ntaub ntawv siv cov kev sib faib faib cov txheej txheem uas siv cov nplooj ntawv qib ntsuas phoo thiab zoo ib yam li MVCC (Multi-Version Concurrency Control) tab sis siv cov kev txheeb xyuas kev lag luam raws li cov yuam sij thiab qhov tseem ceeb hloov pauv ntawm nplooj ntawv teev. Kev nyeem ntawv thiab sau cov haujlwm tau ua nyob rau hauv kev sib txuas nrog lub database snapshot, kev hloov pauv uas pom nyob rau hauv lub ntsiab database tsuas yog tom qab kev sib pauv tiav.
Cov neeg siv khoom tuaj yeem siv peb txoj haujlwm qhib kev lag luam:
- "BEGIN" - kev ua lag luam tsis suav nrog kev nkag mus rau cov ntaub ntawv ntawm lwm tus neeg siv khoom. Yog tias sau ntawv ua haujlwm tau ua nyob rau hauv kev sib pauv, qhov kev sib pauv tuaj yeem cog lus tsuas yog thaum lub sijhawm nws ua tiav tsis muaj lwm yam sau ua haujlwm hauv cov ntaub ntawv.
- "YUAV CONCURRENT" - kev lag luam sau cov ntaub ntawv hais txog kev nkag mus ntawm lwm tus neeg siv khoom. Yog tias sau ntawv ua haujlwm tau ua nyob rau hauv ib qho kev sib pauv, qhov kev sib pauv tuaj yeem cog lus yog tias lwm yam kev hloov pauv tau raug cog lus hauv cov ntaub ntawv txij li lub snapshot tau tsim.
- "TSIS MUAJ TSEEB" - tom qab qhib kev lag luam, nws thaiv kev ua haujlwm los ntawm lwm yam kev lag luam kom txog thaum nws tiav.
HCtree txhawb nqa tus tub qhe replication, uas tso cai rau koj tsiv mus nyob rau lwm qhov chaw khaws ntaub ntawv thiab khaws cov ntaub ntawv thib ob hauv sync nrog cov ntaub ntawv tseem ceeb. HCtree kuj tshem tawm qhov txwv ntawm cov ntaub ntawv loj - tsis yog 32-ntsis cov ntaub ntawv nplooj ntawv txheeb xyuas, HCtree siv 48-ntsis sawv daws yuav, uas ua rau kom cov ntaub ntawv loj tshaj plaws los ntawm 16 tebibytes mus rau 1 exbibyte (million tebibytes). Nws xav tias qhov kev ua tau zoo ntawm SQLite nrog HCtree backend yuav tsis qis dua qhov classic ib leeg-xov rov qab. SQLite cov neeg siv nrog HCtree kev txhawb nqa yuav tuaj yeem nkag mus rau HC-ntoo-raws li databases thiab SQLite databases qub.
Tau qhov twg los: opennet.ru