Qhov twg siv cov khoom pom?

Cov txheej txheem:

Qhov twg siv cov khoom pom?
Qhov twg siv cov khoom pom?

Video: Qhov twg siv cov khoom pom?

Video: Qhov twg siv cov khoom pom?
Video: Tshuaj theem vim li cas thiaj tau nqi ?/ Siv kho mob dab tsi?/paris polyphylla use for? 2024, Hlis ntuj nqeg
Anonim

Nyob hauv cov ntaub ntawv warehouses, koj tuaj yeem siv cov khoom siv los saib ua ntej thiab khaws cov ntaub ntawv sib sau xws li cov khoom muag. Cov ntsiab lus pom hauv cov cheeb tsam no feem ntau hu ua cov ntsiab lus, vim tias lawv khaws cov ntaub ntawv sau tseg. Lawv tuaj yeem siv los ua precompute koom nrog lossis tsis muaj kev sib sau.

Dab tsi yog qhov pom pom thiab yuav siv thaum twg?

Views feem ntau yog siv thaum cov ntaub ntawv yuav tsum nkag mus tsis tu ncua thiab cov ntaub ntawv hauv cov lus tau hloov kho tas li. Ntawm qhov tod tes, Materialized Views yog siv thaum cov ntaub ntawv yuav tsum tau nkag mus ntau zaus thiab cov ntaub ntawv hauv cov lus tsis tau hloov kho tas li.

Dab tsi yog qhov txiaj ntsig ntawm kev pom zoo?

qhov txiaj ntsig loj ntawm Cov Khoom Siv Saib yog nrawm nrawm heev ntawm cov ntaub ntawv sau ua ke, vim nws yog precomputed thiab khaws cia, ntawm tus nqi ntawm kev ntxig / hloov tshiab / rho tawm. Lub database yuav khaws cov Materialized View sync nrog cov ntaub ntawv tiag tiag, tsis tas yuav rov tsim lub log, cia cov ntaub ntawv ua rau koj.

Qhov twg zoo dua los yog pom pom zoo?

Materialized View teb sai dua hauv kev sib piv rau Saib. Nws yog vim hais tias cov materialized saib yog precomputed thiab li no, nws tsis nkim sij hawm nyob rau hauv kev daws cov lus nug los yog koom nyob rau hauv cov lus nug uas tsim cov Materialized View. Uas tig tau teb sai dua rau cov lus nug uas ua rau pom pom.

Vim li cas peb siv cov khoom pom hauv cov ntaub ntawv faib tawm?

Raws li nrog rau lwm cov ntaub ntawv ntawm precomputation, cov neeg siv cov ntaub ntawv feem ntau siv cov ntaub ntawv pom zoo rau qhov ua tau zoo, piv txwv li ua ib daim ntawv ntawm kev ua kom zoo. … Thaum twg cov lus nug lossis qhov hloov tshiab hais txog qhov pom zoo tib yam lub rooj virtual, DBMS hloov cov no mus rau hauv cov lus nug lossis hloov tshiab tawm tsam cov rooj hauv qab.

Pom zoo: