DKNF rephrasing of PJNF Definition Let R=(A1,A2,...,A)be a relation schema.Let dom(A;)denote the domain of attribute A,and let all these domains be infinite.Then all domain constraints D are of the form A,dom(A). Let the general constraints be a set G of functional,multivalued,or join dependencies.If Fis the set of functional dependencies in G,let the set K of key constraints be those nontrivial functional dependencies in F+of the form a→R. Schema Ris in PJNF if and only if it is in DKNF with respectto D,K. and G. Database System Concepts-7th Edition 28.13 @Silberschatz,Korth and SudarshanDatabase System Concepts - 7 28.13 ©Silberschatz, Korth and Sudarshan th Edition DKNF rephrasing of PJNF Definition ▪ Let R = (A1 , A2 ,..., An ) be a relation schema. Let dom(Ai ) denote the domain of attribute Ai , and let all these domains be infinite. Then all domain constraints D are of the form Ai  dom (Ai ). ▪ Let the general constraints be a set G of functional, multivalued, or join dependencies. If F is the set of functional dependencies in G, let the set K of key constraints be those nontrivial functional dependencies in F+ of the form  → R. ▪ Schema R is in PJNF if and only if it is in DKNF with respect to D, K, and G