Video: Vim li cas cov ntaub ntawv sib raug zoo thiaj li muaj zog?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Relational databases yog muaj zog vim hais tias lawv xav tau ob peb kev xav txog yuav ua li cas cov ntaub ntawv muaj feem xyuam los yog yuav ua li cas nws yuav muab rho tawm los ntawm database . Vim li ntawd, tib yam database tuaj yeem pom ntau yam sib txawv. Ib qho tseem ceeb ntawm kev sib raug zoo systems yog hais tias ib leeg database tuaj yeem kis tau thoob plaws ntau lub rooj.
Hauv qhov no, dab tsi yog qhov txiaj ntsig ntawm kev sib raug zoo database?
Lwm qhov tseem ceeb qhov zoo ntawm kev sib raug zoo databases suav nrog lawv cov kev ua tau zoo, lub zog, thiab kev txhawb nqa rau cov thev naus laus zis tshiab, xws li kev yoog raws thiab muaj peev xwm ua tau raws li txhua hom kev lag luam. cov ntaub ntawv xav tau. Cov databases no yog scalable thiab muab kev txhawb nqa rau kev siv cov kev faib tawm.
Ib yam li ntawd, lub peev xwm loj ntawm DBMS yog dab tsi thiab vim li cas kev sib raug zoo DBMS thiaj li muaj zog? Cov kev sib txheeb database yog thawj txoj hauv kev tsim thiab tswj cov ntaub ntawv niaj hnub no hauv cov ntaub ntawv xov xwm vim nws yog yog li ntawd hloov tau thiab siv tau. Nws npaj cov ntaub ntawv nyob rau hauv ob-dimensional tables hu ua kev sib raug zoo, nrog cov kab thiab txhua kab.
Ua raws li qhov xav tau, vim li cas peb thiaj xav tau cov ntaub ntawv sib txheeb?
Qhov zoo ntawm kev sib txheeb databases Lub ntsiab kom zoo dua ntawm kev sib txheeb databases yog tias lawv pab kom cov neeg siv tau yooj yim categorize thiab khaws cov ntaub ntawv uas canlater yuav queried thiab lim kom rho tawm cov ntaub ntawv tshwj xeeb forreports. Relational databases kuj yog ib qho yooj yim mus cuag andaren tsis cia siab rau lub cev lub koom haum.
Excel puas yog cov ntaub ntawv sib raug zoo?
Excel cov lub koom haum qauv qiv nws tus kheej zoo li cas databases ua haujlwm. Ib daim ntawv qhia, ib leeg, yog a database , tab sis tsis yog a kev sib raug zoo ib. Cov Relationaldatabase yog ib qho kev sib txuas ntawm Master spreadsheet table and all of its Slave tables or spreadsheets.
Pom zoo:
Vim li cas cov ntaub ntawv tiaj tus tsis zoo dua li cov ntaub ntawv sib raug zoo?
Ib lub rooj ua ntaub ntawv tiaj tus yog qhov tseem ceeb rau kev sau cov ntaub ntawv tsawg. Tab sis cov ntaub ntawv loj loj tuaj yeem ua tsis tau raws li nws siv ntau qhov chaw thiab nco dua li cov ntaub ntawv sib txheeb. Nws kuj yuav tsum tau muab cov ntaub ntawv tshiab ntxiv txhua zaus koj nkag mus rau cov ntaub ntawv tshiab, qhov kev sib raug zoo database tsis
Vim li cas kev sib raug zoo algebra siv nyob rau hauv kev sib raug zoo database tswj?
RELATIONAL ALGEBRA yog ib hom lus nug uas siv dav heev. Nws sau cov xwm txheej ntawm kev sib raug zoo raws li kev tawm tswv yim thiab muab qhov tshwm sim ntawm kev sib raug zoo raws li cov zis. Nws siv ntau yam haujlwm los ua qhov haujlwm no. Relational algebra operations yog ua recursively ntawm kev sib raug zoo
Dab tsi yog qhov txawv ntawm kev sib raug zoo unary kev sib raug zoo binary thiab kev sib raug zoo ternary?
Kev sib raug zoo tsis sib xws yog thaum ob tus neeg koom hauv kev sib raug zoo yog tib lub koom haum. Piv txwv li: Cov ncauj lus yuav yog qhov yuav tsum tau ua ua ntej rau lwm yam kev kawm. Kev sib raug zoo ternary yog thaum peb lub koom haum koom nrog kev sib raug zoo
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
Vim li cas peb thiaj siv cov ntaub ntawv sib raug zoo?
Cov ntaub ntawv sib raug zoo tso cai rau koj kom yooj yim nrhiav cov ntaub ntawv tshwj xeeb. Nws kuj tso cai rau koj txheeb raws li ib daim teb thiab tsim cov ntawv ceeb toom uas tsuas muaj qee qhov chaw los ntawm txhua cov ntaub ntawv. Relational databases siv cov ntxhuav los khaws cov ntaub ntawv