Normal Forms

Question

If a relation has no functional dependency than what is the normal form of this relation???

Comments

"A relation has no functional dependency" - is Never Possible.

Every relation ALWAYS has at least Trivial Functional Dependencies. 

Better question is "If a relation has No Nontrivial functional dependency, then what is the Normal Form of the relation?".. & the answer is BCNF, because there would be No Violation of BCNF in case of No Nontrivial FD.

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Answer 1

A relation have always  trivial functional dependency. 

A trivial functional dependency always is in BCNF.

Example

R(ABC)

AB--->B like

Comments

Please reply.

If a relation have always trivial function dependency then why not every relation is in BCNF??

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Not every relation has trivial dependencies only...they can have non trivial dependencies also....here it is so happened that if no FDs on a relation exist ( obviously trivial FDs always both and combining all the attributes will act as a key for the table)!

Answer 2

1>trivial dependencies is like,

sid---->sid

sname---->sname

cid------>cid

the meaning fo trivial dependencies is self-depending,i can be determined by itself,

 

#non_trivial_FD- 

sid------>sname

sid_cid---->sname 
 

 

#semi_non_trivial_fd

AB---->BC

C------>AC

 

If a relation has no functional dependency than what is the normal form of this relation???

for_example lets take a table

x	y
5	7
5	7
6	4
6	4

 Now from above table we can say "x---->y"

and according to your question ''If a relation has no functional dependency'' its mean that we have only 

x

5

5

6

8

#NORMALIZATION- is used to reduce redundancy in the database relations, and redundancy occurs if 2 or more relation stored in a single database, and can not use fds here  bczz we have only one row in the table,so how can we think about normal forms