Third Normal Form Assistance

Question

I have the following:

R = (A,B,C,D,E,F,G) FD = (A->B, C->D, E->F, ACE->G)

I'm struggling with the decomposition into 3NF. I've read through several of the other posts and managed to confuse myself. Any assistance is greatly appreciated.

Answer 1

The only key is ACE.

• R = (ACE BDFG)

A->B is a partial key dependency. R is not in 2NF.

• R₁ = (ACE DFG)
• R₂ = (A B)

R₂ is in 5NF. R₁ still has a partial key dependency: C->D.

• R₃ = (ACE FG)
• R₂ = (A B)
• R₄ = (C D)

R₂ didn't change; it's still in 5NF. R₄ is in 5NF. R₃ still has a partial key dependency: E->F.

• R₅ = (ACE G)
• R₂ = (A B)
• R₄ = (C D)
• R₆ = (E F)

All four of those are now in 5NF. (So they're also in 3NF.)