Video: Cov indexes ua haujlwm li cas hauv MongoDB?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Index txhawb kev ua tau zoo ntawm cov lus nug hauv MongoDB . Tsis muaj indexes , MongoDB yuav tsum ua ib tug sau sau scan, i.e. luam theej duab txhua daim ntawv nyob rau hauv ib tug sau, rau xaiv cov ntaub ntawv uas phim cov nqe lus nug. Cov qhov ntsuas khaws cov nqi ntawm ib qho chaw tshwj xeeb lossis cov teb, txiav txim los ntawm tus nqi ntawm daim teb.
Xav txog qhov no, kev siv qhov ntsuas hauv MongoDB yog dab tsi?
Ib Index hauv MongoDB yog cov ntaub ntawv tshwj xeeb uas tuav cov ntaub ntawv ntawm ob peb lub teb ntawm cov ntaub ntawv uas cov qhov ntsuas yog tsim. Index txhim kho qhov nrawm ntawm kev tshawb nrhiav hauv cov ntaub ntawv vim tias tsis yog kev tshawb nrhiav tag nrho cov ntaub ntawv, kev tshawb fawb tau ua nyob rau hauv indexes uas tuav ob peb teb xwb.
Ib qho tseem yuav nug, MongoDB puas tuaj yeem siv ntau qhov ntsuas? MongoDB tuaj yeem siv kev sib tshuam ntawm ntau indexes ua kom tiav cov lus nug. Feem ntau, txhua qhov ntsuas kev sib tshuam muaj ob indexes ; txawm li cas los xij, MongoDB tau ua hauj lwm ntau /nested qhov ntsuas kev sib tshuam los daws cov lus nug.
Ib yam li ntawd, tib neeg nug, hom kev ntsuas twg MongoDB txhawb nqa?
Geospatial Index: Txhawm rau nug cov ntaub ntawv geospatial, MongoDB siv ob hom indexes -2d indexes (nyeem ua ob D indexes ) thiab 2d kheej kheej (nyeem raws li ob lub D) indexes . Ntawv nyeem Index : Cov indexes hauv MongoDB tshawb nrhiav cov ntaub ntawv kab hauv ib phau. Hashed Index : MongoDB txhawb nqa hash-based sharding thiab muab hashed indexes.
MongoDB indexes khaws cia nyob qhov twg?
Yog li thaum indexes yog tsim, lawv kuj yog khaws cia nyob rau hauv lub disk, Tab sis thaum ib daim ntawv thov khiav, raws li kev siv nquag thiab txawm tias nkag tau sai dua lawv tau thauj mus rau hauv RAM tab sis muaj qhov sib txawv ntawm kev thauj khoom thiab tsim. Kuj loading ib qhov ntsuas Nws tsis zoo li kev thauj khoom lossis cov ntaub ntawv rau hauv RAM.
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