Video: Dab tsi yog cov ntaub ntawv tsis pom kev zam?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Qhov no kev zam yog pov tseg thaum lub sij hawm ua tsis tau tejyam los qhib lub ntaub ntawv denoted los ntawm lub npe pathname. Tsis tas li ntawd, qhov no kev zam tuaj yeem muab pov tseg thaum daim ntawv thov sim qhib a ntaub ntawv rau kev sau ntawv, tab sis ntaub ntawv yog nyeem nkaus xwb, los yog tso cai ntawm lub ntaub ntawv ua tsis yog tso cai rau ntaub ntawv yuav tau nyeem los ntawm txhua daim ntawv thov.
Tsuas yog li ntawd, vim li cas cov ntaub ntawv tsis pom yog kuaj xyuas?
Txij li thaum FileNotFoundException yog subclass ntawm IOException, peb tuaj yeem hais qhia IOException hauv cov npe cuam tshuam thiab ua rau cov kev pab cuam saum toj no compiler-tsis muaj yuam kev. 2) Unchecked yog cov kev zam uas yog tsis kuaj ntawm lub sijhawm sau. Lub compiler tso cai rau nws los sau, vim ArithmeticException yog ib qho unchecked kev zam.
Tom qab ntawd, lo lus nug yog, tsis muaj kev zam Java? Dab tsi yog qhov tsim nyog Java kev zam pov rau thaum lub ntsiab lus thov tsis muaj nyob ? Pov los qhia tias ib txoj hauv kev tau dhau qhov kev sib cav tsis raug cai lossis tsis tsim nyog. Txoj kev tau muab qhov kev sib cav siv tau, nws tsuas yog tsis tau muaj hauv database.
Ib yam li ntawd ib tug yuav nug, qhov kev zam raug pov tseg thaum muaj kev sim nkag mus rau cov ntaub ntawv uas tsis muaj nyob?
FileNotFoundException
Koj ua li cas IO kev zam?
Thaum twg IOException pov tseg IOException yog lub hauv paus kev zam chav kawm siv rau tuav kev ua tsis tiav. Nyob rau hauv ib txoj kev ntawm chav kawm, sim, ntes , thiab thaum kawg thaiv tuav cov kev zam . Daim ntawv thov api chav kawm txoj kev pov ib qho IOException los yog nws cov subclass. Sim ntes Thaum kawg thaiv cov cai tau qhia hauv qab no hauv cov xwm txheej sib txawv.
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
Dab tsi yog qhov sib txawv ntawm cov ntaub ntawv sib sau ua ke thiab cov ntaub ntawv tsis sib xws?
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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 VM Series koj yuav tsum xav txog yog tias koj xav tau cov ntawv thov host uas xav tau kev ua haujlwm siab IO rau cov ntaub ntawv tsis tu ncua?
Teb: VM series uas koj yuav tsum yog xav txog yog tias koj xav tau txais cov ntawv thov uas xav tau kev ua haujlwm siab rau cov ntaub ntawv tsis tu ncua yog VMware workstation, Oracle VM virtual box lossis Microsoft Azure suav. Cov khoom siv no muaj qhov yooj yim tshaj plaws ntawm kev ua haujlwm hosting
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