Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Translating functional dependencies into 3rd normal form

I have this problem decomposing a relation schema into a set of schemas that are in 3NF.

I have this relation schema: R= (A, B, C, D, E, F)
With the following set F of functional dependencies:

A → ABCDEF
B → C
D → E

Can anyone help me out?

like image 572
Alphonse Avatar asked Nov 21 '25 05:11

Alphonse


1 Answers

RA = (A, B, D, F)
RB = (B, C)
RD = (D, E)

Why? 3NF requires the removal all transitive dependencies.

In R, C is transitively dependent on A through B, and the same is true for E through D. To remove those properties, you need to decompose the tables such that those transitive relationships are removed, which you do by extracting the table and using the middle term as keys.

like image 117
Nick Larsen Avatar answered Nov 24 '25 11:11

Nick Larsen



Donate For Us

If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!