Boyce-Codd Normal Form A relation schema R is in BCNF with respect to a set F of functional dependencies if for all functional dependencies in F+of the form 0→B where a R and B R,at least one of the following holds: aB is trivial (i.e.,Bc a) a is a superkey for R Example schema not in BCNF: bor loan =customer_id,loan_number,amount because loan_number->amount holds on bor_loan but loan number is not a superkey Database System Concepts-5th Edition,Oct 5,2006 7.17 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 5 7.17 ©Silberschatz, Korth and Sudarshan th Edition, Oct 5, 2006 Boyce-Codd Normal Form  →  is trivial (i.e.,   )  is a superkey for R A relation schema R is in BCNF with respect to a set F of functional dependencies if for all functional dependencies in F+ of the form  →  where   R and   R, at least one of the following holds: Example schema not in BCNF: bor_loan = ( customer_id, loan_number, amount ) because loan_number → amount holds on bor_loan but loan_number is not a superkey