Video: Hom ntaub ntawv twg yog tiag?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Tiag tiag . Ib ' Tiag tiag ' hom ntaub ntawv yog tus lej cov ntaub ntawv uas muaj cov lej lej. Nws yuav siv thaum xav tau kev nthuav dav ntxiv thiab tus lej tag nrho yuav tsis muab cov ntaub ntawv txaus.
Ua raws li qhov no saib, dab tsi yog hom ntaub ntawv tiag tiag hauv SQL?
Cov ntaub ntawv tiag tuaj yeem tuav tus nqi 4 bytes loj, txhais tau tias nws muaj 7 tus lej ntawm qhov tseeb (tus lej ntawm tus lej mus rau sab xis ntawm tus lej lej). Nws tseem yog tus lej ntab ntab uas zoo ib yam rau cov lus taw qhia ntab ntab ntab (24).
Ib yam li ntawd, cov ntaub ntawv hom piv txwv yog dab tsi? A hom ntaub ntawv yog a hom ntawm cov ntaub ntawv . Qee yam hom ntaub ntawv suav nrog integers, floating point tooj, cim, hlua, thiab arrays. Tej zaum lawv kuj yuav hais meej dua hom , xws li hnub tim, timestamps, boolean qhov tseem ceeb, thiab varchar ( sib txawv tus cwj pwm) formats.
Kuj kom paub yog, dab tsi yog tus lej tiag cov ntaub ntawv?
A hom ntaub ntawv tiag yog a hom ntaub ntawv siv nyob rau hauv ib tug computer program los sawv cev ib qho approximation ntawm a tus lej tiag . Vim lub tus lej tiag tsis suav tau, khoos phis tawj tsis tuaj yeem sawv cev rau lawv raws nraim siv cov ntaub ntawv tsawg kawg nkaus. Feem ntau, lub computer yuav siv qhov kev kwv yees kwv yees rau a tus lej tiag.
Dab tsi yog hom ntaub ntawv tiag tiag hauv C?
Cov no yog qhov tseem ceeb hom ntaub ntawv hauv C xws li integer(int), floating point(float), character(char) and void.
Pom zoo:
Hom ntaub ntawv twg cov ntaub ntawv mining tsim?
Cov ntaub ntawv Mining yog txhua yam hais txog kev tshawb nrhiav qhov tsis xav txog / yav dhau los tsis paub txog kev sib raug zoo ntawm cov ntaub ntawv. Nws yog ntau txoj kev qhuab qhia uas siv tshuab kev kawm, txheeb cais, AI thiab kev siv tshuab database. Cov kev nkag siab tau muab los ntawm Cov Ntaub Ntawv Mining tuaj yeem siv rau kev lag luam, tshawb nrhiav kev dag ntxias, thiab tshawb pom kev tshawb fawb, thiab lwm yam
Dab tsi yog lub hom phiaj ntawm delimiters nyob rau hauv cov ntawv sau npe ob hom ntawv cov ntaub ntawv delimiters?
Cov ntaub ntawv delimited yog cov ntawv nyeem siv los khaws cov ntaub ntawv, uas txhua kab sawv cev rau ib phau ntawv, tuam txhab, lossis lwm yam, thiab txhua kab muaj cov teb sib cais los ntawm tus lej
Lub sijhawm tiag tiag hom yog dab tsi?
Lub sij hawm yog siv los piav txog ntau yam sib txawv hauv computer. Piv txwv li, lub sijhawm ua haujlwm tiag tiag yog cov tshuab uas teb rau cov tswv yim tam sim. Realtime kuj tseem tuaj yeem xa mus rau cov xwm txheej simulated los ntawm lub computer ntawm tib qhov ceev uas lawv yuav tshwm sim hauv lub neej tiag tiag
Lub sijhawm tiag tiag cov ntaub ntawv warehouse yog dab tsi?
Lub tsev khaws ntaub ntawv ntawm lub sijhawm tiag tiag yog ib qho uas tau txais, ntxuav, hloov pauv, khw muag khoom, thiab tshaj tawm cov ntaub ntawv hauv lub sijhawm. Ib lub tsev khaws ntaub ntawv nquag, ntawm qhov tod tes, ua haujlwm hauv hom lus teb tsis yog lub sijhawm nrog ib lossis ntau dua OLTP systems
Hom ntaub ntawv twg ntawm Hadoop tso cai rau columnar cov ntaub ntawv cia hom?
Columnar ntaub ntawv tawm tswv yim (Parquet, RFile) Qhov tseeb hotness nyob rau hauv cov ntaub ntawv tawm tswv yim rau Hadoop iscolumnar cov ntaub ntawv cia. Yeej qhov no txhais tau hais tias tsis yog cia li khaws cov kab ntawm cov ntaub ntawv nyob ib sab rau ib leeg koj kuj khaws cov kab ntawv nyob ib sab. Yog li datasets tau muab faib ua ob qho tib si horizontally thiab vertically