I need help with the following question including the \"why concisely\" part: Fo

Question

I need help with the following question including the "why concisely" part:

For each of the following given relational schemas (R1, R2, R3, R4) with primary key and set of functional dependencies, please indicate what the highest normal form is for each relational schema and why concisely:


a. R1(A, B, C, D)
Key: AB
Functional Dependencies: AB --> C, AB --> D, A --> C, B --> D

b. R2(A, B, C, D)
Key: AB
Functional Dependencies: AB --> C, C --> D

c. R3(A, B, C, D)
Key: AB
Functional Dependencies: AB --> C, AB --> D, C --> B

d. R4(A, B, C, D)
Key: AB
Functional Dependencies: AB --> C, AB --> D

Explanation / Answer

c. R3(A, B, C, D)
Key: AB
Functional Dependencies: AB ? C, AB ? D, C? B

AB ? C : In third normal form

AB ? D : in third normal form

C? B : In first normal form as non key attribute is depend on part of primary key

d. R4(A, B, C, D)
Key: AB
Functional Dependencies: AB ? C, AB ? D

AB ? C : In third normal form

AB ? D : In third normal form

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