0 like 0 dislike
asked in Computer Science by (474k points)
What is second normal form?

1 Answer

0 like 0 dislike
answered by (474k points)
Second normal form (2NF) is a normal form used in database normalization. 2NF was originally defined by E.F. Codd in 1971.[1]

To qualify for second normal form a relation must:

(1) be in first normal form (1NF)

(2) not have any non-prime attribute that is dependent on any proper subset of any candidate key of the relation. A non-prime attribute of a relation is an attribute that is not a part of any candidate key of the relation.

Put simply, a relation is in 2NF if it is in 1NF and every non-prime attribute of the relation is dependent on the whole of every candidate key. Note that it does not put any restriction on the non-prime to non-prime attribute dependency. That is addressed in Third normal form.
Welcome to Free Homework Help, where you can ask questions and receive answers from other members of the community. Anybody can ask a question. Anybody can answer. The best answers are voted up and rise to the top. Join them; it only takes a minute:

10.2k questions

9.2k answers


3.2k users


Free Hit Counters