I truly have no idea how you can figure this out. I have go through all of the normal forms, but nonetheless have trouble understanding it. I really hope someone might help me comprehend it.
Relation schema is R(A,B,C,D,E,F) with (A -> BCD, BC -> P, B -> D, D -> A).
What's the greatest normal form and why?
Any assistance is appreciated, thanks.
F does not appear anywhere.
You will find two options. Either that's the purpose of the exercise, or even the being active is problematic.
In my opinion the greatest Normal Form you might achieve here could be 3NF or BCNF. I only say the reason being:
- 1NF necessitates the removal of repeating groups and characteristics are atomic. You don't have any repeating groups so the needs for 1NF happen to be met automatically.
- 2NF and 3NF cope with how relations are built regarding Functional Dependencies. I help you possess the following Functional Dependencies referred to: (A -> BCD, BC -> P, B -> D, D -> A). Given these, you might structrue relations into 2NF, 3NF and perhaps BCNF.
- 4NF and above cope with multi-valued details. You haven't referred to these so it's reasonable to presume you will find none. Some may reason that any BCNF relation where no multi-valued details exist can also be in 4NF - I'd rather not enter into that certain since it just boils lower to some "glass half full/empty" kind of arguement.
I haven't taken time to work through all the FD's (it's your homework in the end), however i would pay attention
towards the FD's:
BC -> D,
D -> A and
A -> B.
The greatest Normal form is 1NF here, because you will find total 3 candidate secrets that are AF,DF,BF. So in the given FD set there's partial FD exist, and according to rule , Partial FDs aren't permitted within the 2NF. so greatest Normal Form is 1NF.