GATE | GATE-CS-2009 | Question 60

Let R and S be relational schemes such that R={a,b,c} and S={c}. Now consider the following queries on the database:
gateqa

IV) SELECT R.a, R.b
       FROM R,S
            WHERE R.c=S.c

Which of the above queries are equivalent?
(A) I and II
(B) I and III
(C) II and IV
(D) III and IV


Answer: (A)

Explanation: I and II describe the division operator in Relational Algebra and Tuple Relational Calculus respectively. See Page 3 of this and slide numbers 9,10 of this for more details.

Quiz of this Question



My Personal Notes arrow_drop_up

Recommended Posts:



0 Average Difficulty : 0/5.0
No votes yet.






User Actions