Dab tsi yog xauv hauv SQL Server?

2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47

Xauv : Xauv yog ib tug mechanism los xyuas kom meej cov ntaub ntawv sib xws. SQL Server locks khoom thaum qhov kev sib pauv pib. Thaum qhov kev hloov pauv tiav lawm, SQL Server tso tawm kaw khoom. Tshwj xeeb (X) Locks : Thaum no xauv hom tshwm sim, nws tshwm sim los tiv thaiv lwm yam kev hloov pauv lossis nkag mus rau a kaw khoom.

Tsis tas li ntawd, yog dab tsi yog xauv rau hauv database?

A database xauv yog siv rau " xauv "Qee cov ntaub ntawv hauv a database yog li ntawd ib leeg xwb database tus neeg siv / ntu tuaj yeem hloov kho cov ntaub ntawv tshwj xeeb. Locks feem ntau yog tso tawm los ntawm ROLLBACK lossis COMMIT SQL nqe lus.

Tsis tas li ntawd, yog dab tsi yog xauv thiab thaiv hauv SQL Server? Xauv yog lub mechanism uas SQL Server siv los tiv thaiv cov ntaub ntawv kev ncaj ncees thaum lub sijhawm ua lag luam. Thaiv . Thaiv (los yog thaiv lub xauv ) tshwm sim thaum ob txheej txheem xav tau kev nkag mus rau tib daim ntaub ntawv ib txhij yog li ib txheej txheem xauv cov ntaub ntawv thiab lwm tus yuav tsum tau tos rau lwm tus kom tiav thiab tso tawm cov xauv.

Ib yam li ntawd, nws tau nug, hom kev xauv hauv SQL Server yog dab tsi?

SQL neeg rau zaub mov muaj ntau dua 20 ntau hom kev ntsuas phoo tab sis tam sim no cia peb tsom mus rau qhov tseem ceeb tshaj plaws

• Shared locks (S). Cov xauv no tau txais los ntawm cov neeg nyeem thaum nyeem cov haujlwm xws li SELECT.
• Exclusive xauv (X).
• Hloov tshiab xauv (U).
• Lub hom phiaj xauv (IS, IX, IU, thiab lwm yam).

Qhov hloov tshiab xauv hauv SQL Server yog dab tsi?

Hloov tshiab xauv yog internal xauv ua kom tsis txhob muaj kev tsis sib haum xeeb i.e rau kev xav tias 3 txheej txheem ntawm 5 xav tau hloov tshiab cov ntaub ntawv. Peb cov txheej txheem no thov cov server los muab qhov tshwj xeeb xauv qe cov server tsis tuaj yeem tawm tau yooj yim vim tias 2 txheej txheem tseem tab tom nyeem cov ntaub ntawv thiab sib koom xauv tseem nyob.