Ukuxhomeka okusebenzayo kusiza ukugwema ukuphindaphinda kwedatha
Ukuthembela okusebenzayo ku-database kudinga isethi yezinkinga phakathi kwezimfanelo. Lokhu kwenzeka uma isici esisodwa ebuhlotsheni obuhlukile sinquma esinye isici. Lokhu kungabhalwa A -> B okusho ukuthi "B isebenze ngokusekelwe ku-A." Lokhu kubizwa nangokuthi kuncike ekuxhasweni kwedatha .
Kulobudlelwano, i-A inquma ukubaluleka kwe-B, ngenkathi i-B ixhomeke ku-A.
Kungani Ukuxhomeka Kwemisebenzi Kubalulekile kuDesign Design
Ukuthembela komsebenzi kusiza ukuqinisekisa ukuqinisekiswa kwedatha.Cabangela itafula Abasebenzi ababala izici ezifaka inombolo yezokuphepha komphakathi (SSN), igama, usuku lokuzalwa, ikheli nokunye okunye.
Isici se-SSN sizonquma ukubaluleka kwegama, usuku lokuzalwa, ikheli kanye namanye amanani, ngoba inombolo yokuphepha yomphakathi ihlukile, kuyilapho igama, usuku lokuzalwa noma ikheli lingase lingabi. Singayibhala kanje:
I-SSN -> igama, usuku lokuzalwa, ikheli
Ngakho-ke, igama, usuku lokuzalwa nekheli lisebenza ngokuxhomeke ku-SSN. Noma kunjalo, isitatimende esilandelayo (igama -> SSN) alilona iqiniso ngoba abasebenzi abangaphezu kwesinye bangaba negama elifanayo kodwa ngeke babe ne-SSN efanayo. Faka enye indlela, indlela ekhonakala ngayo, uma siyazi ukubaluleka kwesici se-SSN, singathola inani lamagama, usuku lokuzalwa nekheli. Kodwa uma thina kunalokho sazi ukubaluleka kwegama kuphela igama, asikwazi ukubona i-SSN.
Uhlangothi lwesobunxele lokuxhomeka kokusebenza lungabandakanya okungaphezulu kweyodwa. Ake sithi sinebhizinisi enezindawo eziningi. Singase sibe neThebula labasebenzi kanye nezimfanelo zomsebenzi, isihloko, umnyango, indawo kanye nomphathi.
Isisebenzi sinquma indawo esebenza ngayo, ngakho-ke kunokwethenjelwa:
isisebenzi -> indawo
Kodwa indawo ingaba nemenenja engaphezu kweyodwa, ngakho-ke umsebenzi nomnyango ndawonye banquma umphathi:
isisebenzi, umnyango -> umphathi
Ukuxhomeka kokusebenza nokusebenza
Ukuxhomekeka okusebenzayo kunomthelela kulokho okubizwa ngokuthi ukugcinwa kwemininingwane yedatha, okuqinisekisa ukuthembeka kwedatha nokunciphisa ukulungiswa kwedatha. Ngaphandle kokujwayelekile, akukho isiqinisekiso sokuthi idatha ku-database inembile futhi iyathembeka.