Dab tsi yog lub hnub qub schema nyob rau hauv cov ntaub ntawv warehouse?
Dab tsi yog lub hnub qub schema nyob rau hauv cov ntaub ntawv warehouse?

Video: Dab tsi yog lub hnub qub schema nyob rau hauv cov ntaub ntawv warehouse?

Video: Dab tsi yog lub hnub qub schema nyob rau hauv cov ntaub ntawv warehouse?
Video: Yog hmoov dab tsi - Gao Nou Kue ft. Mang Vang (Official Music Video) New song 2020 2024, Kaum ib hlis
Anonim

Hauv cov ntaub ntawv warehouse thiab kev txawj ntse ua lag luam (BI), a lub hnub qub schema yog daim ntawv yooj yim tshaj plaws ntawm tus qauv dimension, uas cov ntaub ntawv yog npaj rau qhov tseeb thiab qhov ntev. Qhov tseeb yog ib qho xwm txheej uas suav los yog ntsuas, xws li kev muag lossis kev nkag. Cov lus tseeb kuj muaj ib lossis ntau qhov ntsuas.

Tom qab ntawd, ib tug kuj yuav nug, dab tsi yog snowflake schema nyob rau hauv cov ntaub ntawv warehouse?

Hauv cov ntaub ntawv warehouse , snowflakeing yog ib daim qauv ntawm qhov loj me uas qhov ntev tau muab khaws cia rau hauv ntau lub rooj sib tham. A snowflake schema yog variation ntawm lub hnub qub schema . Ib lub hnub qub schema khaws txhua tus cwj pwm rau qhov loj me rau hauv ib lub rooj denormalized ("flattened").

Tsis tas li, koj ua li cas los tsim lub hnub qub schema hauv cov ntaub ntawv warehouse? Cov kauj ruam hauv kev tsim Star Schema:

  1. Txheeb xyuas cov txheej txheem kev lag luam rau kev txheeb xyuas (xws li kev muag khoom).
  2. Txheeb xyuas qhov ntsuas lossis qhov tseeb (muag duas).
  3. Txheeb xyuas qhov ntev rau qhov tseeb (cov khoom loj, qhov loj me, qhov ntev, qhov ntev, lub koom haum qhov ntev).
  4. Sau cov kab uas piav qhia txhua qhov loj me.

Ib yam li ntawd ib tug yuav nug, uas schema yog qhov zoo tshaj plaws rau cov ntaub ntawv warehouse?

Snowflake Schema
Hom Datawarehouse Zoo siv rau datawarehouse core kom yooj yim kev sib raug zoo (ntau: ntau)
Koom nrog Ntau dua ntawm Joins
Dimension rooj Tej zaum nws yuav muaj ntau tshaj ib lub rooj rau txhua qhov ntev

Lub hnub qub schema piv txwv yog dab tsi?

Hauv Lub hnub qub Schema , Cov ntaub ntawv txheej txheem kev lag luam, uas tuav cov ntaub ntawv ntau txog kev lag luam yog muab faib rau hauv cov lus tseeb, thiab qhov ntev uas yog cov yam ntxwv piav qhia txog cov ntaub ntawv tseeb. Tus nqi muag, muag kom muaj nuj nqis, nyob deb, ceev, qhov hnyav, thiab ntsuas qhov hnyav yog tsawg piv txwv ntawm cov ntaub ntawv tseeb hauv lub hnub qub schema.

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