Dab tsi ua kom kab txav ua hauv Oracle?
Dab tsi ua kom kab txav ua hauv Oracle?

Video: Dab tsi ua kom kab txav ua hauv Oracle?

Video: Dab tsi ua kom kab txav ua hauv Oracle?
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Thaum koj ntxiv cov lus " pab kom kab txav "los tsim cov lus teev lus, koj yog muab Oracle tso cai los hloov ROWID's. Qhov no tso cai Oracle rau condense rooj kab thiab ua kom yooj yim rau reorganize rooj.

Yog li ntawd, Oracle kab txav yog dab tsi?

Cov Kab Mov tau qhia los txhawb qhov UPDATE ntawm ib qho tseem ceeb muab faib-yog li lub rooj kab yog txav los ntawm ib lub rooj muab faib mus rau lwm qhov. Raws li ntawm Oracle tso 11g2, Kab Mov yog xaiv tau thiab xiam oob qhab ib lub neej ntawd. Nws tuaj yeem qhib rau ib lub rooj nrog cov lus tsis tseem ceeb ALTER TABLE.

Ib yam li ntawd, qhov poob qis hauv Oracle database yog dab tsi? Oracle Ntu Txo Qhov chaw feature tau qhia los ntawm Oracle database version 10g. Nws yog siv rau reclaiming tsis siv / fragmented qhov chaw los ntawm database cov khoom xws li rooj, index-organized table (IOT), index, muab faib, sub-partition, materialized saib los yog materialized saib cav.

Kuj kom paub, dab tsi yog kev siv flashback hauv Oracle?

Oracle Database muaj ib pab pawg ntawm cov yam ntxwv, paub sib sau ua ke flashback , uas muab txoj hauv kev los saib cov xeev yav dhau los ntawm cov khoom siv database, lossis xa rov qab cov khoom siv database rau lub xeev dhau los, tsis tas siv cov khoom siv ib txwm siv rov qab los.

Peb puas tuaj yeem hloov kho kab sib faib hauv Oracle?

tshwm sim thaum koj sim ua hloov tshiab tus nqi ntawm a muab faib tus yuam sij kem . Qhov no yuav ua rau muaj kev cuam tshuam INSERT. ROWID ntawm kab tau muab thaum kab tau tso thawj zaug, thiab nws tsis ua hloov . Yog li ntawd, los ntawm lub neej ntawd, Oracle yuav tsis lees txais ib qho DML uas yuav ua rowid hloov.

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