Multiple choice

Consider a relation scheme R = (A, B, C, D, E, H), on which the following functional dependencies hold: (A ® B, BC ® D, E ® C, D ® A). What are the candidate keys of R?

  1. AE, BE

  2. AE, BE, DE

  3. AEH, BEH, BCH

  4. AEH, BEH, DEH

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is a duplicate of 336217. The candidate keys are found by taking the closure of sets containing E and H (as they are not on the right side of any FD). Closure(AEH), Closure(BEH), and Closure(DEH) all result in the set of all attributes.