Video: Puas yog Presto cache cov ntaub ntawv?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Presto khw muag khoom nruab nrab cov ntaub ntawv thaum lub sijhawm ua haujlwm hauv nws qhov tsis cache . Txawm li cas los xij, nws tsis yog txhais tau tias ua haujlwm caching tov los yog ib tug pheej cia txheej.
Hauv qhov no, yog Presto database?
Presto yog ib qho kev faib tawm uas khiav ntawm Hadoop, thiab siv cov qauv zoo ib yam li kev ua haujlwm loj heev (MPP) database tswj qhov system. Ua Presto Extensible rau txhua qhov chaw cov ntaub ntawv, nws tau tsim nrog kev cia khoom abstraction kom nws yooj yim los tsim pluggable connectors.
Tsis tas li ntawd, puas siv MapReduce? Presto yog ib qho qhib qhov chaw sib luag SQL execution engine. Tsis zoo li Hive, Presto tsis yog siv tus daim ntawv qhia txo lub moj khaum rau nws ua. Hloov chaw, Presto ncaj qha nkag mus rau cov ntaub ntawv los ntawm ib tug tshwj xeeb faib lus nug cav uas zoo ib yam li cov uas pom nyob rau hauv coj mus muag parallel RDBMSs.
Yog li ntawd, vim li cas Presto ceev?
Yog vim li cas #1: Presto yog Plenty Ceev ceev MapReduce ua haujlwm ntawm tus qauv "rub" thiab rub cov ntaub ntawv los ntawm cov haujlwm ua ntej. Ib theem nce siab tau txais cov ntaub ntawv los ntawm nws cov theem qis, yog li cov ntaub ntawv nruab nrab tuaj yeem hla ncaj qha, yog li ua rau cov lus nug tseem ceeb. sai dua.
Apache Presto ua haujlwm li cas?
Presto yog ib tug faib system uas khiav ntawm ib pawg ntawm cov nodes. Presto cov Kev faib tawm cov lus nug cav tau ua kom zoo rau kev sib tham sib txheeb xyuas thiab txhawb nqa tus qauv ANSI SQL, suav nrog cov lus nug nyuaj, sib sau ua ke, koom nrog, thiab lub qhov rais ua haujlwm. Presto architecture yog yooj yim thiab extensible.
Pom zoo:
Dab tsi yog qhov sib txawv ntawm pab pawg cov ntaub ntawv thiab cov ntaub ntawv tsis yog pawg?
Ob leeg yog cov ntaub ntawv muaj txiaj ntsig ntawm cov ntaub ntawv tab sis qhov sib txawv ntawm lawv yog cov ntaub ntawv tsis muaj ntaub ntawv yog rawdata. Qhov no txhais tau hais tias nws nyuam qhuav tau sau tab sis tsis txheeb rau hauv ib pawg lossis cov chav kawm. Ntawm qhov tod tes, groupeddata yog cov ntaub ntawv uas tau teeb tsa ua pawg los ntawm cov ntaub ntawv nyoos
Puas yog TIFF cov ntaub ntawv yog cov ntaub ntawv vector?
TIF - (los yog TIFF) sawv cev rau Tagged Image File Format thiab yog cov ntaub ntawv loj loj. Cov ntaub ntawv TIF feem ntau yog siv rau cov duab hauv kev luam ntawv vim tias cov ntaub ntawv tsis poob cov ntaub ntawv lossis zoo li JPEG ua. Nws yog cov ntaub ntawv vector uas tuaj yeem muaj cov ntawv nyeem nrog rau cov duab thiab cov duab kos
Puas yog array yog cov qauv ntaub ntawv lossis hom ntaub ntawv?
Ib qho array yog homogeneous cov ntaub ntawv qauv (cov ntsiab lus muaj tib cov ntaub ntawv hom) uas khaws cov khoom sib txuas ntawm cov khoom sib txuas ua ke - faib rau hauv kev sib txuas ua ke.Txhua yam khoom ntawm cov array tuaj yeem nkag tau los ntawm kev siv nws tus lej (piv txwv li, index). Thaum koj tshaj tawm ib qho array, koj teem nws qhov loj me
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