When the constraint expression of a query is not a CNF (Conjunctive Normal Form),it is generally transformed into an equivalent DNF (disjunctive normal form)an union of CNFs .是什么意思_When the constraint expression of a query is not a CNF (Conjunctive Normal Form),it is generally transformed into an equivalent DNF (disjunctive normal form)an union of CNFs .在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句