Cov txheej txheem:
- Vim li cas COMMIT thiab rollback nqe lus tsim nyog?
- Dab tsi yog qhov cuam tshuam ntawm daim ntawv rov qab?
- Yuav ua li cas yog tias koj tsis thim rov qab kev lag luam?
- Peb puas tuaj yeem thim rov qab tom qab cog lus?
Video: Vim li cas peb thiaj xav tau rov qab?
2024 Tus sau: Fiona Howard | [email protected]. Kawg hloov kho: 2024-01-10 06:38
Lub hom phiaj ntawm rollback yog "rov qab" ib qho thiab tag nrho cov ntaub ntawv hloov kho tau ua tiav ntawm BEGIN TRANSACTION thiab ROLLBACK hauvrooj plaub yog tias ib chav haujlwm ua haujlwm tsis ua haujlwm vim txhua yam yuam kev.
Vim li cas COMMIT thiab rollback nqe lus tsim nyog?
A COMMIT nqe lus yog siv los khaws cov kev hloov pauv ntawm kev hloov pauv tam sim no mus tas liDaim ntawv Rollback yog siv los tshem tawm tag nrho cov kev hloov pauv tam sim no. … Yog tias tag nrho cov nqe lus raug ua tiav yam tsis muaj qhov yuam kev, daim ntawv COMMIT yuav cawm lub xeev mus tas li.
Dab tsi yog qhov cuam tshuam ntawm daim ntawv rov qab?
Cov txiaj ntsig ntawm qhov rov qab yog yog tias nqe lus ntawd tsis tau khiav Qhov kev ua haujlwm no yog ib nqe lus-qib rollback. Qhov yuam kev nrhiav tau thaum lub sij hawm SQL nqe lus ua tiav ua rau nqe lus-qib rollbacks. Ib qho piv txwv ntawm qhov yuam kev no yog sim ntxig tus nqi sib npaug hauv tus yuam sij tseem ceeb.
Yuav ua li cas yog tias koj tsis thim rov qab kev lag luam?
9 Teb. Tsuav koj tsis COMMIT lossis ROLLBACK ib qho kev sib pauv, nws tseem " khiav" thiab muaj peev xwm tuav xauv Yog tias koj tus neeg siv khoom (daim ntawv thov lossis tus neeg siv) kaw qhov kev sib txuas rau cov ntaub ntawv ua ntej cog lus, ib qho tseem khiav lag luam yuav muab dov rov qab thiab txiav.
Peb puas tuaj yeem thim rov qab tom qab cog lus?
Tom qab koj ua qhov kev hloov pauv, cov kev hloov pauv tau pom rau lwm tus neeg siv cov lus uas ua tiav tom qab kev cog lus. Koj tuaj yeem thim rov qab (tsis ua) txhua yam kev hloov pauv tau ua thaum lub sijhawm ua lag luamnrog ROLLBACK nqe lus (saib ROLLBACK.
Pom zoo:
Vim li cas peb thiaj xav tau kev faib tawm hauv lub txim?
Partitioning pab tseem ceeb txo qhov nyiaj ntawm I / O cov haujlwm ua kom cov ntaub ntawv nrawm nrawmSpark yog raws li lub tswv yim ntawm cov ntaub ntawv hauv zos. Nws qhia tau hais tias rau kev ua haujlwm, cov neeg ua haujlwm nodes siv cov ntaub ntawv uas nyob ze rau lawv.
Vim li cas peb thiaj xav tau kev sib sab?
Nyob hauv xov tooj cua sib txuas lus, ib sab band yog ib pawg ntawm cov zaus siab dua lossis qis dua tus neeg nqa khoom zaus, uas yog qhov tshwm sim ntawm cov txheej txheem hloov kho. Cov sidebands nqa cov ntaub ntawv xa los ntawm xov tooj cua teeb liabCov sidebands suav nrog tag nrho cov spectral Cheebtsam ntawm cov teeb liab modulated tsuas yog cov cab kuj .
Vim li cas peb thiaj xav tau isomorphism?
Vim yog ib qho isomorphism khaws cia qee yam qauv ntawm pawg lossis pawg lej, nws feem ntau siv los qhia cov teeb meem nyuaj rau ib qho yooj yim lossis zoo dua-paub teeb kom tsim tau cov khoom qub. Isomorphisms yog ib yam ntawm cov kev kawm nyob rau hauv pab pawg neeg txoj kev xav .
Vim li cas thiaj tuaj yeem rov ua lub hlwb rov qab tau?
Cov roj teeb rov qab tau khaws lub zog los ntawm cov tshuaj tiv thaiv rov qab tau, uas tso cai kom them rov qab khaws cia dua tom qab lub roj teeb tas lawm . Lub hlwb puas tuaj yeem rov them tau? Ib lub xovtooj ntawm tes lossis roj teeb yog ib qho uas tsis tuaj yeem rov qab tau yooj yim tom qab siv ib zaug, thiab muab pov tseg tom qab tso tawm.
Vim li cas peb thiaj xav tau kev xav?
Lub hom phiaj tseem ceeb ntawm kev paub daws teeb meem yog zais cov ntsiab lus tsis tsim nyog los ntawm cov neeg sivAbstraction yog xaiv cov ntaub ntawv los ntawm lub pas dej loj dua los qhia cov ntsiab lus ntawm cov khoom rau tus neeg siv.
