Leli glosari lihlanganisa imigomo yolwazi kanye nemigomo esetshenziselwa yonke inhlobo yolwazi. Akubandakanyi imigomo ethize kwizinhlelo ezithile noma imininingwane yolwazi.
I-ACID
Imodeli ye-ACID yokuklanywa kwedatha iqinisa ubuqotho bemininingwane ngokusebenzisa i- atomicity , ukuvumelana , ukuhlukaniswa, nokuqina:
- I-Atomicity: Ukuthengiselana kwemininingwane ngayinye kumele kulandele konke okungaveli noma okungenalutho, okusho ukuthi uma kunoma iyiphi ingxenye yokuthengiswa kwehluleka, konke ukuthengiswa kwehluleka.
- Ukubambisana : Ukuthengiswa kwemininingwane ngayinye kufanele kulandelwe yonke imithetho echazwe yedatha; noma yikuphi ukuthengiswa okungaphula le mithetho akuvumelekile.
- Ukuhlukaniswa : Ukuthengiswa kwedatha ngayinye kuzokwenzeka ngaphandle kokunye ukuthengiselana. Isibonelo, uma ukuthengiselana okuningi kuhanjiswa ngesikhathi esifanayo, i-database izovimbela noma yikuphi ukuphazamiseka phakathi kwabo.
- Ukuguqulwa : Ukuthengwa kwemininingwane ngayinye kuyoba khona ngokuphelele kunoma yikuphi ukuhluleka kwedatha, nge-backups noma ezinye izindlela.
Isici
Isici se- database siyisici se-database entity. Kalula nje, umphumela yikholomu etafuleni lemininingwane, eyaziwa ngokuthi yiyona nhlangano.
Ukuqinisekisa
I-database isebenzisa ubuqiniso ukuqinisekisa ukuthi abasebenzisi abagunyaziwe kuphela abangakwazi ukufinyelela ku-database noma izici ezithile ze-database. Isibonelo, abaphathi bangagunyazwa ukufaka noma ukuhlela idatha, kanti abasebenzi abavamile bangakwazi ukubuka idatha kuphela. Ubuqiniso buqaliswa ngamagama abasebenzisi namaphasiwedi.
BASE Model
Imodeli ye-BASE iye yasungulwa njengenye indlela emfanekisweni we-ACID ukuze isebenze izidingo ze-database ye-SQL lapho idatha ingakhiwe ngendlela efanayo edingekayo yolwazi oluhlobene. Iziqalo zayo eziyinhloko yi-Basic Disponibilité, State Soft, kanye Nokuzihlanganisa Kwamanje:
- Ukutholakala okuyisisekelo : I-database iyatholakala futhi isebenza, ixhaswe ngezinye izikhathi ngokuphindaphinda kwedatha kusakazwe kumaseva amaningana.
- I-Soft State : Ukuphikisa imodeli ye-ACID yokuhambisana okuqinile, le nqubo ithi isimo akufanele ngaso sonke isikhathi sihlale sihambisana futhi ukuthi noma yikuphi ukuvumelana okuhambisanayo kuwumthwalo wemininingwane yomuntu ngamunye noma umthuthukisi.
- Ukubambisana okuqhubekayo : Ngenye iphuzu elingalindelekile, iphuzu elizayo, i-database izothola ukuvumelana.
Izithiyo
Isivimbezelo sedatha yeqoqo yemigomo echaza idatha evumelekile. Kunezinhlobo eziningi zezinkinga. Izithiyo eziyinhloko yizi:
- Izithiyo eziyingqayizivele : Insimu kumele iqukathe inani eliyingqayizivele etafuleni.
- Hlola izithiyo : Insimu ingaqukatha izinhlobo ezithile zedatha ngisho nemigomo ethile evumelekile.
- IZINQUBO ZESIFUNDO : Insimu izoba nenani elizenzakalelayo uma lingenalo inani elikhona; lokhu kuqeda inani le-NULL.
- IZIMPILO ZOKUPHUMA KWESIKHATHI ESIKHULU : Isihluthulelo esiyinhloko kumele sibe sehlukile.
- IZINHLOKO EZIKHULULEKILE : Ukhiye wangaphandle kufanele ufanise ukhiye oyinhloko okhona kwenye ithebula.
I-Database Management System (i-DBMS)
I-DBMS yisofthiwe elawula zonke izici zokusebenza nedatha, ukugcina nokugcina idatha ukuze kuqinisekiswe imithetho yokuthembeka kwedatha, ukunikeza amafomu okufaka idatha nokuphathwa. I-Relational Database Management System (i-RDBMS) isebenzisa imodeli ehambisanayo yamatafula nobuhlobo phakathi kwabo.
Ibhizinisi
Inhlangano imane nje ithebula ku-database. Ichazwa isebenzisa isichazamazwi sobudlelwane be-Entity-Relationship, okuyinto uhlobo lomdwebo obonisa ubudlelwano phakathi kwamatafula egciniwe.
Ukuxhomeka kokusebenza
Ukuvimbela ukusebenza okusebenzayo kusiza ukuqinisekisa ukuqinisekiswa kwedatha, futhi kukhona lapho isici esisodwa sinquma ukubaluleka kwesinye, sichazwa njenge- A -> B esho ukuthi inani le-A lithatha ukubaluleka kweB, noma ukuthi iB "ixhomeke ekusebenzeni" ku-A Isibonelo, ithebula eyunivesithi efaka amarekhodi abo bonke abafundi angase abe nokuthembela okusebenzayo phakathi kwe-ID yomfundi kanye negama lomfundi, okungukuthi i-ID yomfundi ehlukile izobheka inani legama.
Inkomba
Inkomba iyisakhiwo sedatha esisiza imibuzo ngesivinini sedatha yamadokhumenti amakhulu. Abathuthukisi be-database badala inkomba kumakholomu athile etafuleni. Inkomba ibamba amanani ekholomu kodwa iqondisa nje idatha kuleyo yonke ithebula, futhi ingasesha ngokufanele futhi ngokushesha.
Ukhiye
Isihluthulelo yinkundla yedatha enenjongo yokukhomba irekhodi ngokukhethekile. Usizo lwezinsiza luqinisekisa ukuthembeka kwedatha futhi ugweme ukuphindaphindiwe. Izinhlobo eziyinhloko zezikhiye ezisetshenziswe ku-database ziyizihluthulelo zokuzikhethela, izinkinobho eziyisihluthulelo ezingokhiye zangaphandle.
- Izihluthulelo zokukhethwa : Iqoqo lamakholomu angakwazi ukukhomba irekhodi ngokukhethekile futhi okukhethwa kukho ukhiye oyinhloko.
- Izihluthulelo eziyinhloko : Isihluthulelo esikhethwe ukukhomba kuphela irekhodi etafuleni. Lesi sikhiye asikwazi uku-NULL.
- Ukhiye wangaphandle : Isihluthulelo esixhumanisa irekhodi kwirekhodi kwelinye ithebula. Isihluthulelo sangaphandle setafula kufanele sibe khona njengokhiye oyinhloko wenye itafula.
Ukujwayelekile
Ukwenza i-database ibe yinto ejwayelekile ukuklama amatafula (ubudlelwane) namakholomu (izimfanelo) ngendlela yokuqinisekisa ukuthembeka kwedatha nokugwema ukuphindaphindiwe. Amazinga okuqala okujwayelekile okuyiyona ifomu yokuqala ejwayelekile (1NF), ifomu lesibili elijwayelekile (2NF), ifomu lesithathu elijwayelekile (3NF) ne-Boyce-Codd Form Form (BCNF).
I-NoSQL
I-NoSQL iyimodeli ye-database eyenzelwe ukubhekana nesidingo sokugcina idatha engakhiwe njenge-imeyili, okuthunyelwe kwezokuxhumana, ividiyo noma izithombe. Esikhundleni sokusebenzisa i-SQL kanye nesimo esiqinile se-ACID ukuqinisekisa ubuqotho bemininingwane, i-NoSQL ilandela imodeli encane ye-BASE. I-NoSQL database schema ayisebenzisi amathabula ukugcina idatha; Kunalokho, kungase kusetshenziswe umkhiqizo / ukwakhiwa kwamanani noma amagrafu.
Null
Inani le- NULL livame ukudideka ukuze lisho "akekho" noma i-zero; Nokho, empeleni kusho "angaziwa." Uma insimu inenani le-NULL, ingumnikazi wendawo ye-value engaziwa. Ulimi Lokusebenza Oluhlelekile (SQL) lusebenzisa ama-NULL NABASEBENZISI be-NULL ukuhlola ama-null amanani.
Umbuzo
Umbuzo wesisekelo sendlela abasebenzisi abasebenzisana ngayo nedatha. Ngokuvamile kubhalwe ku-SQL futhi kungaba yinkinga ekhethiwe noma umbuzo wesenzo . Idatha yokucela imibuzo ekhethiwe esuka ku-database; ukuguqulwa kombuzo wesenzo, ukuvuselela noma ukungeza idatha. Ezinye yolwazi zinikeza amafomu afihla i-semantics yombuzo, okuvumela abasebenzisi ukuthi bacele kalula ulwazi ngaphandle kokuqonda i-SQL.
I-Schema
Isikweletu se-database yisakhiwo samatafula, amakholomu, ubudlelwano, nezinkinga ezakha i-database. I-Schemas ivame ukuchazwa besebenzisa isitatimende SQL CREATE.
Inqubo egcinwe
Inqubo egcinwe ngumbuzo oqanjwe ngaphambili, noma isitatimende se-SQL esingabelwa kuzo zonke izinhlelo nabasebenzisi ku-System Management System. Izinqubo ezigcinwe zithuthukisa ukusebenza kahle, usizo lukuqinisekisa ukuthembeka kwedatha nokuthuthukisa umkhiqizo.
Ulimi Lokusebenza Oluhlelekile
Ulimi Lokusebenza Oluhlelekile , noma i-SQL, ulimi oluvame ukusetshenziswa kakhulu ukufinyelela idatha kusuka ku-database. Ulimi Lokulawulwa Kwemininingwane (DML) luqukethe i-subset yemilayezo ye-SQL esetshenziswe kaningi futhi ihlanganisa ukhethe, QAPHELA, QAPHELA bese UCULA.
I-Trigger
I-trigger inqubo egcinwe ukusetha inikeze umcimbi othize, ngokuvamile ukushintsha kwedatha yethebula. Isibonelo, i-trigger ingase iklanyelwe ukubhala kugijimi, ukuqoqa izibalo noma ukubala inani.
Buka
Ukubukwa kwedatha kuyisethi ehlungiwe yedatha eboniswe kumsebenzisi wokugcina ukuze kufihlwe ukudida kwedatha futhi ivuselele isipiliyoni somsebenzisi. Umbono ungajoyina idatha kusuka kumatafula amabili noma ngaphezulu futhi iqukethe i-subset yolwazi.