Cov txheej txheem:

Dab tsi yog tsom xam hauv redshift?
Dab tsi yog tsom xam hauv redshift?

Video: Dab tsi yog tsom xam hauv redshift?

Video: Dab tsi yog tsom xam hauv redshift?
Video: Leng Yang - Yog Vim Dab Tsi (Official Full Song | Nkauj Tawm Tshiab) 2020/05/24 2024, Kaum ib hlis
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Redshift Analyze hais kom ua yog siv los sau cov txheeb cais ntawm cov rooj uas nug tus neeg npaj siv los tsim cov lus nug kom ua tiav txoj kev npaj siv Redshift Piav hais kom ua. Txheeb xyuas hais kom tau txais cov qauv ntaub ntawv los ntawm cov ntxhuav, xam thiab khaws cov txheeb cais hauv STL_ANALYZE rooj.

Hauv qhov no, dab tsi yog redshift nqus tsev vacuum?

Amazon Redshift tam sim no cia li khiav lub VACUUM DELETE kev ua haujlwm kom rov qab tau qhov chaw disk nyob los ntawm kab uas tau cim rau kev tshem tawm los ntawm kev hloov kho yav dhau los thiab DELETE cov haujlwm. VACUUM DELETE yog teem caij los khiav raws li cov lus nug load thiab tus naj npawb ntawm cov kab deleted hauv cov ntxhuav.

Tsis tas li, koj yuav rho tawm lub rooj hauv redshift li cas? Rau rho tawm row ib Redshift rooj , siv cov DELETE Los ntawm nqe lus: DELETE Los ntawm cov khoom nyob qhov twg product_id=1; Cov lus nyob qhov twg yog xaiv tau, tab sis feem ntau koj yuav xav tau, tshwj tsis yog tias koj xav tau tiag tiag rho tawm txhua kab los ntawm rooj.

Ib yam li ntawd, koj yuav ua li cas kho cov lus nug redshift?

Sab saum toj 14 Performance Tuning Techniques rau Amazon Redshift

  1. Taw qhia.
  2. Tshem tawm cov sij hawm tos tos los ntawm kev sib tw queue qhov suav rau qhov siab tshaj plaws concurrency.
  3. Txo cov lus nug raws li disk los ntawm kev muab lub cim xeeb txaus rau koj cov kab.
  4. EVEN-based Distribution.
  5. KEY-raws li kev faib tawm los ua JOINs sai dua.
  6. Downsides ntawm KEY-raws li kev faib tawm.

Kev hloov pauv liab hauv physics yog dab tsi?

' Liab hloov ' yog lub ntsiab lus tseem ceeb rau astronomers. Lub sij hawm tuaj yeem nkag siab qhov tseeb - lub wavelength ntawm lub teeb yog ncab, yog li lub teeb pom tau tias yog ' ua haujlwm ' rau ntawm liab ib feem ntawm spectrum. Ib yam zoo sib xws tshwm sim rau lub suab nthwv dej thaum lub hauv paus ntawm lub suab txav mus rau tus neeg soj ntsuam.

Pom zoo: