Cov txheej txheem:

Puas tshem tawm qhov tsis sib xws ntawm cov ntaub ntawv?
Puas tshem tawm qhov tsis sib xws ntawm cov ntaub ntawv?
Anonim

Data tu (cleansing) yog cov txheej txheem ntawm kev tshem tawm qhov yuam kev thiab daws qhov tsis sib xws hauv cov ntaub ntawv ua ntej thauj khoom mus rau hauv ib qho chaw khaws cia. Lub hom phiaj ntawm kev tu cov ntaub ntawv, uas yog tshwj xeeb tshaj yog yuav tsum tau thaum sib koom ua ke heterogeneous cov ntaub ntawv qhov chaw, yog kev txhim kho cov ntaub ntawv zoo (Rahm, 2000).

Dab tsi yog qhov tsis sib xws ntawm cov ntaub ntawv?

Data inconsistency yog ib qho xwm txheej uas muaj ntau lub rooj nyob rau hauv ib lub database uas cuam tshuam nrog tib cov ntaub ntawv tab sis tej zaum yuav tau txais los ntawm ntau inputs. Inconsistency feem ntau yog compounded los ntawm cov ntaub ntawv redundancy.

Dab tsi ua rau cov ntaub ntawv tsis sib xws?

Database inconsistency tuaj yeem tshwm sim yog tias koj txav cov ntaub ntawv, rooj, daim ntawv thov lossis lwm yam khoom siv los ntawm kev siv cov lus txib ua haujlwmes tsis yog cov kev txhawb nqa Ingres. … Ib cov ntaub ntawv database tuaj yeem ua tsis zoo los ntawm kev kho vajtse lossis software tsis ua haujlwm ntawm ntau yam.

Dab tsi yog cov ntaub ntawv tsis sib haum nrog piv txwv?

Data Redundancy ua rau cov ntaub ntawv tsis sib xws. … Piv txwv – Yog tias peb muaj qhov chaw nyob ntawm ib tug neeg hauv ntau lub rooj thiab thaum peb hloov nws hauv ib lub rooj thiab hauv lwm lub rooj nws yuav tsis hloov kho yog li muaj teeb meem ntawm cov ntaub ntawv tsis sib xws yuav tshwm sim.

Koj tiv thaiv cov ntaub ntawv tsis sib xws li cas?

3 Qhov Kev Pom Zoo Tshaj Plaws ntawm Txoj Kev los txo qhov tsis sib xws pom nyob hauv Databases

  1. Read ib txoj hlua.
  2. nthuav cov ntawv luv thiab cov ntawv sau.
  3. Tshem tawm cov suab nrov: piv txwv li, hloov pauv A' thiab A, thiab hloov pauv a' thiab a'.
  4. Txoj hlua mus rau tus lej qis.
  5. Tshem cov lus tso tseg.

Pom zoo: