Cov txheej txheem:
Video: Cov ntawv nyeem hauv cov ntaub ntawv yog dab tsi?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
TXOJ CAI yog tsev neeg ntawm hom kab npaj ua tus muaj peev xwm ua cim cia. Qhov tseeb TEXT kab hom yog ntawm plaub hom -TINYTEXT, TXOJ CAI , MEDIUMTEXT thiab LONGTEXT. Plaub TEXT hom zoo sib xws heev; qhov sib txawv tsuas yog qhov siab tshaj plaws ntawm cov ntaub ntawv txhua tus tuaj yeem khaws cia.
Ib yam li ntawd, cov ntaub ntawv hom ntawv hauv SQL yog dab tsi?
TXOJ CAI (loj) Tuav txoj hlua nrog qhov ntev tshaj plaws ntawm 65, 535 bytes. BLOB (loj) Rau BLOBs (Binary Loj OBjects). Tuav mus txog 65,535 bytes ntawm cov ntaub ntawv.
Number data hom yog dab tsi? Cov ntaub ntawv naj npawb yog tus lej khaws cia rau hauv kab ntawv database. Cov no hom ntaub ntawv feem ntau yog pawg los ntawm: Qhov tseeb hom lej yog INTEGER, BIGINT, DECIMAL, NUMERIC , NUMBER , thiab NYIAJ. Kwv yees li hom lej , qhov tseem ceeb qhov twg qhov precision yuav tsum tau khaws cia thiab cov nplai tuaj yeem ntab.
Ua li no, cov ntawv nyeem hauv database yog dab tsi?
A ntawv nyeem yog ib ntu ntawm cov cim (lossis cov cim) kos los ntawm cov tsiaj ntawv. A text database yog ib qhov system uas tuav ib tug (feem ntau loj) ntawv nyeem sau thiab muab ceev thiab raug nkag mus rau nws. Ob lub hom phiaj no kuj yog orthogonal, thiab ob qho tib si tseem ceeb heev kom tau txais txiaj ntsig los ntawm qhov ntawv nyeem sau.
5 hom ntaub ntawv yog dab tsi?
Hom ntaub ntawv uas muaj xws li:
- Tus lej.
- Floating point tooj.
- Cim.
- Txoj hlua.
- Boolean.
Pom zoo:
Dab tsi yog cov ntaub ntawv hloov pauv hauv cov ntaub ntawv khaws cia?
Cov ntaub ntawv hloov pauv yog cov ntaub ntawv uas tau tsim nyob rau hauv daim ntawv thov kev sib ntsib, uas tsis tau khaws cia hauv cov ntaub ntawv tom qab daim ntawv thov raug txiav
Dab tsi yog kev noj cov ntaub ntawv hauv cov ntaub ntawv loj?
Cov ntaub ntawv ingestion yog tus txheej txheem ntawm tau txais thiab import cov ntaub ntawv rau tam sim ntawd siv los yog cia nyob rau hauv ib tug database. Txhawm rau noj ib yam dab tsi yog 'coj ib yam dab tsi los yog nqus ib yam dab tsi.' Cov ntaub ntawv tuaj yeem xa tawm hauv lub sijhawm tiag tiag lossis noj hauv cov khoom siv
Dab tsi yog cov ntaub ntawv thev naus laus zis hauv kev tswj cov ntaub ntawv xov xwm?
Kev tswj cov ntaub ntawv xov xwm (MIS) yog hais txog cov txheej txheem loj siv los ntawm kev lag luam lossis kev lag luam, thaum cov ntaub ntawv thev naus laus zis (IT) yog ib feem ntawm cov txheej txheem uas siv los sau thiab xa cov ntaub ntawv. Cov Ntaub Ntawv Technology txhawb nqa thiab pab txhawb kev ua haujlwm ntawm qhov system ntawd
Vim li cas kem taw qhia cov ntaub ntawv khaws cia ua cov ntaub ntawv nkag ntawm disks sai dua li kab qhia cov ntaub ntawv khaws cia?
Kem oriented databases (aka columnar databases) yog qhov tsim nyog rau kev ntsuas kev ua haujlwm ntau dua vim tias cov ntaub ntawv hom ntawv (kem hom) qiv nws tus kheej kom nrawm dua cov lus nug ua - scans, aggregation thiab lwm yam. Ntawm qhov tod tes, kab oriented databases khaws ib kab (thiab tag nrho nws. kab) contiguously
Dab tsi yog cov teeb meem ntawm kev tswj cov ntaub ntawv hauv cov ntaub ntawv ib txwm muaj?
Nyob rau tib lub sijhawm, qhov kev tswj hwm cov ntaub ntawv ib puag ncig tsim teeb meem xws li cov ntaub ntawv rov ua dua thiab tsis sib xws, cov kev pab cuam-cov ntaub ntawv dependence, inflexibility, tsis muaj kev ruaj ntseg, thiab tsis muaj cov ntaub ntawv sib qhia thiab muaj