Video: PL SQL cov ntaub ntawv yog dab tsi?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
PL / SQL Cov Ntaub Ntawv . A sau tseg yog ib pawg ntawm cov ntaub ntawv ntsig txog cov khoom khaws cia hauv thaj chaw, txhua tus muaj nws tus kheej lub npe thiab hom ntaub ntawv. Cov ntaub ntawv yog tsim los ntawm ib pawg ntawm cov teb, zoo ib yam li cov kab hauv a kab . Cov% ROWTYPE attribute cia koj tshaj tawm a PL / SQL cov ntaub ntawv uas sawv cev a kab nyob rau hauv ib lub rooj database, tsis sau tag nrho cov kab.
Ib yam li ntawd, kev siv cov ntaub ntawv hauv PL SQL yog dab tsi?
PL / SQL cov ntaub ntawv pab koj ua kom yooj yim rau koj cov cai los ntawm kev hloov ntawm qib teb mus rau sau tseg - theem kev ua haujlwm. PL / SQL ntawv muaj peb hom cov ntaub ntawv : table-based, cursor-based, programmer-defined. Ua ntej siv a sau tseg , koj yuav tsum tshaj tawm nws.
Qhov thib ob, % hom hauv PL SQL yog dab tsi? PL / SQL ntawv % HOM Yam ntxwv. Cov% HOM attribute tso cai rau koj tshaj tawm qhov tsis tu ncua, sib txawv, los yog parameter los ntawm tib cov ntaub ntawv hom raws li yav tas los tshaj tawm kuj sib txawv, cov ntaub ntawv, nested table, los yog database kem.
Kuj kom paub, yog Cov Ntaub Ntawv hauv Oracle PL SQL?
A PL / SQL cov ntaub ntawv yog ib qho kev sib xyaw cov ntaub ntawv qauv uas yog ib pab pawg neeg muaj feem xyuam cov ntaub ntawv khaws cia hauv teb. Txhua qhov chaw nyob hauv PL / SQL cov ntaub ntawv muaj nws lub npe thiab cov ntaub ntawv hom.
Dab tsi yog hom ntaub ntawv hauv Oracle nrog piv txwv?
A Hom ntaub ntawv yog cov ntaub ntawv complex hom uas tso cai rau tus programmer tsim cov ntaub ntawv tshiab hom nrog cov qauv kab uas xav tau. Hom ntaub ntawv tsuas yog txhais tau tias cov ntaub ntawv tshiab hom . Ib zaug lub hom ntaub ntawv yog tsim, nws yuav muab khaws cia raws li cov ntaub ntawv tshiab hom hauv database thiab tib yam yuav tsum tau siv los tshaj tawm qhov sib txawv hauv cov kev pab cuam.
Pom zoo:
Cov ntaub ntawv hom thiab cov qauv ntaub ntawv yog dab tsi?
Cov qauv ntaub ntawv yog ib txoj hauv kev piav qhia txog ib txoj hauv kev los npaj cov ntaub ntawv kom ua haujlwm andalogrithms tuaj yeem siv tau yooj yim dua. Ib hom ntaub ntawv piav qhia txog cov ntaub ntawv uas txhua tus sib koom ua ke. Piv txwv li tus lej cov ntaub ntawv hom piav qhia txhua tus lej uas lub khoos phis tawj tuaj yeem ua tau
Dab tsi yog qhov txawv ntawm XML cov ntaub ntawv thiab cov ntaub ntawv sib txheeb?
Qhov sib txawv loj ntawm XML cov ntaub ntawv thiab cov ntaub ntawv sib txheeb Ib daim ntawv XML muaj cov ntaub ntawv hais txog kev sib raug zoo ntawm cov ntaub ntawv rau ib leeg nyob rau hauv daim ntawv ntawm hierarchy. Nrog rau tus qauv kev sib raug zoo, tib hom kev sib raug zoo uas tuaj yeem txhais tau yog cov lus niam txiv thiab cov rooj sib raug 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
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