Scd2 yog dab tsi?
Scd2 yog dab tsi?

Video: Scd2 yog dab tsi?

Video: Scd2 yog dab tsi?
Video: Working with Slowly Changing Dimensions in Power BI 2024, Kaum ib hlis
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SCD2 : Nws tuav tag nrho keeb kwm hauv lub hom phiaj. Nws tuav keeb kwm los ntawm kev ntxig. cov ntaub ntawv tshiab thiab hloov kho rau txhua qhov kev hloov pauv. SCD3: Nws khaws cov nqi tam sim no thiab yav dhau los tsuas yog hauv lub hom phiaj.

Hais txog qhov no, SCD hom 2 ua li cas?

Ib Qho Hloov Dimension ( SCD ) yog ib qhov loj me uas khaws thiab tswj cov ntaub ntawv tam sim no thiab keeb kwm dhau sij hawm hauv ib lub tsev khaws ntaub ntawv. A Hom 2 SCD khaws tag nrho cov keeb kwm ntawm qhov tseem ceeb. Thaum tus nqi ntawm tus cwj pwm xaiv hloov pauv, cov ntaub ntawv tam sim no yog kaw.

Ib yam li ntawd, scd1 scd2 scd3 yog dab tsi hauv Informatica? SCD Stands rau maj mam hloov qhov ntev. SCD1 : tsuas yog khaws cia cov txiaj ntsig tshiab. Piv txwv li: tus neeg siv khoom chaw nyob hloov peb hloov kho cov ntaub ntawv uas twb muaj lawm nrog qhov chaw nyob tshiab. SCD2 : khaws cov ntaub ntawv keeb kwm thiab cov ntaub ntawv tam sim no los ntawm kev siv.

Tsis tas li ntawd, 3 hom SCD yog dab tsi?

  • Hom 0 – Tsau Dimension. Tsis pub hloov pauv, qhov loj me yeej tsis hloov.
  • Hom 1 – Tsis muaj keeb kwm. Hloov kho cov ntaub ntawv ncaj qha, tsis muaj cov ntaub ntawv keeb kwm muaj txiaj ntsig, tsuas yog lub xeev tam sim no.
  • Hom 2 – Kab Versioning.
  • Hom 3 – Tus nqi dhau los.
  • Hom 4 – Keeb Kwm Table.
  • Hom 6 – Hybrid SCD.

Vim li cas peb thiaj xav tau SCD?

Raws li lub npe qhia, SCD tso cai tswj kev hloov pauv hauv Dimension table hauv cov ntaub ntawv warehouse. Cov no yog qhov loj me uas maj mam hloov nrog lub sijhawm, tsis yog hloov raws li niaj zaus. Thaum koj siv SCDs, koj yeej txiav txim siab li cas koj xav khaws cov ntaub ntawv keeb kwm nrog cov ntaub ntawv tam sim no.

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