The Gateway to Computer Science Excellence
First time here? Checkout the FAQ!
x
+14 votes
598 views

Let $R = (A, B, C, D, E, F)$ be a relation scheme with the following dependencies $C \rightarrow F, E \rightarrow A, EC \rightarrow D, A \rightarrow B $. Which one of the following is a key for $R$?

  1. CD
  2. EC
  3. AE
  4. AC
asked in Databases by Veteran (59.7k points) | 598 views

1 Answer

+18 votes
Best answer
Answer: B

EC is the key for R. Both E and C are not coming on the right hand side of any functional dependency. So, both of them must be present in any key. Now, with EC and the given FDs, we can derive all other attributes making EC a key.
answered by Boss (34k points)
selected by
Answer:

Related questions



Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true

44,062 questions
49,583 answers
162,855 comments
65,776 users