MadeEasy Test Series 2019: Databases - Database Normalization

Question

A3 also deriving {A1,A2,A3} from FD’s...why it is still neglecting BCNF? Is solution wrong or I am misunderstanding?

Comments

A3 is a candidate key, which is the minimal super key. so the answer given is wrong.

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Thanks a lot..that helps

Answer 1

BCNS is getting violated as :

if A1,A2 are primary key then also its candidate key.

it is given that atomic values are allowed so. so it is must be in 1NF.

but always start any form from BCNF then 3NF and so on.

if we check for BCNF it is failing for 2^nd dependency i.e. A3->A1 as A3 is not super key.

Note: I am just giving answer based on the question only i.e. A1 AND A2 are primary keys solution may differs