2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
A materialized view occupies space. Nws tshwm sim tib yam li lub rooj: nws zaum ntawm lub disk thiab tuaj yeem raug ntsuas los yog muab faib.
Peb puas tuaj yeem tshem tawm cov ntaub ntawv los ntawm cov ntaub ntawv pom?
Koj tsis tuaj yeem rho tawm kab los ntawm kev nyeem ntawv nkaus xwb pom. Yog tias koj rho tawm kab los ntawm cov ntawv sau tau pom, tom qab ntawd cov ntaub ntawv tshem tawm cov kab los ntawm cov lus hauv qab ntim. Txawm li cas los xij, cov kev tshem tawm tau sau dhau los ntawm kev ua haujlwm tshiab tom ntej.
Puas views puas nco?
Views yog ib qho tshwj xeeb ntawm cov ntxhuav hauv SQL. … Qhov kev pom yog cov lus nug khaws cia hauv phau ntawv txhais lus cov ntaub ntawv, uas tus neeg siv tuaj yeem nug ib yam li lawv ua ntawm cov ntxhuav. Nws tsis siv lub cev nco, tsuas yog cov lus nug khaws cia hauv phau ntawv txhais lus.
Qhov twg yog qhov zoo dua los yog pom pom zoo?
Views yog virtual nkaus xwb thiab khiav cov lus nug txhais txhua zaus lawv nkag mus. Tsis tas li ntawd thaum koj xav tau kev ua tau zoo ntawm cov ntaub ntawv uas tsis tas yuav hloov mus rau qhov thib ob,cov khoom siv pom zoo dua, tab sis koj cov ntaub ntawv yuav laus dua li qhov kev pom zoo.
Do SQL views siv qhov chaw?
Vim li no, qhov kev pom tsis siv qhov chaw disk rau cov ntaub ntawv khaws cia, thiab nws tsis tsim cov ntawv luam ntawm cov ntaub ntawv uas twb tau khaws cia hauv cov ntxhuav uas nws hais txog (uas qee zaum hu ua lub hauv paus rooj ntawm qhov pom). …
Pom zoo:
Cov ntaub ntawv qhia ntawv puas txhawb nqa cov ntaub ntawv kawm?
Cov ntaub ntawv qhia yuav tsum txhawb nqa txoj kev kawm lub tswv yim, cov hom phiaj thiab cov hom phiaj ntawm Cheeb Tsamthiab cov hom phiaj ntawm cov ntaub ntawv kawm uas cov ntaub ntawv yuav raug siv. … Cov ntaub ntawv qhia yuav tsum ua tau raws li cov qauv zoo ntawm cov ntsiab lus tseeb thiab kev nthuav qhia.
Cov ntawv xov xwm pom nyob rau hauv cov ntawv xov xwm nyob qhov twg?
Editorials feem ntau yog luam tawm ntawm nplooj ntawv nplooj siab, hu ua nplooj ntawv kho, uas feem ntau sau cov ntawv rau tus editor los ntawm cov tswv cuab ntawm pej xeem; nplooj ntawv tawm tsam nplooj ntawv no yog hu ua nplooj ntawv op-ed thiab nquag muaj cov lus xav (li no lub npe xav daim) los ntawm cov kws sau ntawv tsis ncaj qha koom nrog … Lub hom phiaj ntawm kev sau ntawv hauv xov xwm yog dab tsi?
Thaum cov ntaub ntawv tshiab cuam tshuam nrog kev muab cov ntaub ntawv qub no hu ua?
Nrog retroactive cuam tshuam, cov ntaub ntawv tshiab cuam tshuam lub peev xwm rov qab cov ntaub ntawv qub. Nrog kev cuam tshuam tsis zoo, nws yog qhov rov qab: cov ntaub ntawv qub cuam tshuam qhov rov qab los ntawm cov ntaub ntawv tshiab tau kawm.
Puas yog cov ntaub ntawv sib tw cov ntaub ntawv raug cai?
Kev tsim "Cov ntaub ntawv cog lus" yog cov ntaub ntawv sau uas txhais lub luag haujlwm, kev lav phib xaub, thiab "Ua haujlwm" raws li Daim Ntawv Cog Lus Tsim Kho, thiab raug cai lij choj rau ob tog (Tswj thiab tus neeg cog lus).
Cov ntaub ntawv twg muaj cov ntaub ntawv bituminous?
Nws muaj ob chav kawm ntawm cov khoom siv bituminous: (1) asph alt; thiab (2) tar. Cov ntaub ntawv no feem ntau yog siv los ua dej-pov thawj sealants, thiab ua cov ntaub ntawv los tuav cov aggregate ua ke nyob rau hauv bituminous pavements. Dab tsi yog cov khoom siv bituminous?
