Lub hom phiaj ntawm surrogate key yog dab tsi?
Lub hom phiaj ntawm surrogate key yog dab tsi?

Video: Lub hom phiaj ntawm surrogate key yog dab tsi?

Video: Lub hom phiaj ntawm surrogate key yog dab tsi?
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Anonim

A tus tseem ceeb yog tus cim tshwj xeeb uas siv rau hauv cov ntaub ntawv rau cov qauv qauv lossis cov khoom siv. Nws yog ib qho tshwj xeeb tus yuam sij Nws tsuas yog qhov tseem ceeb yog los ua tus cim tseem ceeb ntawm ib qho khoom lossis qhov chaw thiab tsis tau muab los ntawm lwm cov ntaub ntawv hauv cov ntaub ntawv thiab tej zaum yuav lossis tsis raug siv los ua qhov tseem ceeb tus yuam sij.

Ib yam li ntawd, tib neeg nug, qhov txawv ntawm tus yuam sij surrogate thiab tus yuam sij tseem ceeb yog dab tsi?

A thawj tus yuam sij yog ib qho kev txwv tshwj xeeb ntawm ib kab los yog kab ke. A tus tseem ceeb yog txhua kab los yog kab ke uas tuaj yeem tshaj tawm raws li tus thawj tus yuam sij es tsis yog "tiag" lossis ntuj tus yuam sij . Qee lub sij hawm tuaj yeem muaj ntau yam ntuj tso cov yuam sij uas tuaj yeem tshaj tawm tias yog thawj tus yuam sij , thiab tag nrho cov no yog hu ua tus neeg sib tw cov yuam sij.

Qhov thib ob, tus yuam sij surrogate generated li cas? Lawv yog cov yuam sij uas tsis muaj kev sib raug zoo nrog cov seem ntawm cov kab hauv ib lub rooj. Cov tus tseem ceeb tsuas yog tus nqi uas yog tsim tawm thiab tom qab ntawd muab khaws cia nrog lwm cov kab hauv cov ntaub ntawv. Cov tus yuam sij tus nqi yog feem ntau tsim tawm thaum lub sij hawm khiav txoj cai ua ntej cov ntaub ntawv muab tso rau hauv ib lub rooj.

Hais txog qhov no, qhov zoo thiab qhov tsis zoo ntawm kev siv cov yuam sij surrogate generated yog dab tsi?

Surrogate tus yuam sij tiam thiab txoj haujlwm yuav siv lub nra hnyav rau ETL lub moj khaum. Koj yuav tsum tsis txhob siv ntau dhau tus yuam sij surrogate raws li lawv tsis muaj lub ntsiab lus nyob rau hauv cov ntaub ntawv warehouse ntxhuav. Cov ntaub ntawv tsiv teb tsaws yuav nyuaj yog tias koj muaj cov ntaub ntawv sib txuas nrog tus tseem ceeb kab.

Thaum twg koj yuav siv tus yuam sij surrogate hauv cov ntaub ntawv warehouse?

Surrogate yuam sij tau dav siv thiab lees txais tus qauv tsim hauv cov ntaub ntawv warehouses . Nws tau ua raws li tus lej tshwj xeeb txuas nrog txhua tus thiab txhua cov ntaub ntawv nyob rau hauv Dimension table nyob rau hauv ib qho Data Warehouse . Nws koom nrog ntawm qhov tseeb thiab qhov loj me thiab yog qhov tsim nyog los tswj cov kev hloov pauv hauv cov ntsiab lus dimension.

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