IiNkcukacha zeNkcukacha zeNkcukacha eziQinisekisayo kuphela eziLwazi oluQinisekisiweyo
I-Database Consistency ithi kuphela idatha echanekileyo iya kubhalwa kwiziko ledatha. Ukuba kuthengiswa umthengi ophula imithetho ye-database, i-transaction iya kugqitywa kwaye i-database iya kubuyiselwa kwimo yaso yangaphambili. Ngakolunye uhlangothi, ukuba ukuthengiswa ngempumelelo kwenziwa, kuya kuthatha isiseko kwiziko elilodwa elihambelana nemimiselo kolunye uhlangothi oluhambelana nemigaqo.
Ukulungelelaniswa kwedatha akuthethi ukuba ukuthengiselana kuchanekile, kuphela ukuba ukuthengiswa akuzange kuphule imithetho echazwe yiprogram. Ukubambisana kwedatha kubalulekile kuba ilawula idatha ezayo kwaye ilahla idatha engahambelani nemithetho.
Umzekelo weMigaqo yoManyano eMsebenzini
Ngokomzekelo, ikholomu kwisiseko se-database ingaba neemali zengqekembe nje kuphela njenge "iintloko" okanye "imisila." Ukuba umsebenzisi uza kuzama ukubeka "ecaleni," imithetho ehambelana nesiseko sedata ayiyi kuvumela.
Unokuba namava ngemithetho ehambelanayo ngokushiya insimu kwifom yephepha lewebhu engenanto. Xa umntu egcwalisa ifowuni kwi-intanethi aze ayibale ukugcwalisa enye yeendawo ezifunekayo, inani le-NULL liya kwiziko ledatha, okwenza ifom idibene kuze kube yindawo engenanto inayo kuyo.
Ukubambisana isigaba sesibini somzekelo we- ACID (i-Atomicity, i-Consistency, Isolation, Ukuzinza), eyona isethi yezikhokelo zokuqinisekisa ukuchaneka kokuthengiswa kwedatha.