SQL

Question 17

Consider the following SQL query

 select distinct a_l, a₂,........., a_n from r_l, r₂,........, r_m where P

For an arbitrary predicate P, this query is equivalent to which of the following relational algebra expressions?

Question 17 Explanation:

If we want to get distinct elements then we need to perform cross product in between the relations r₁,
r₂, …. r_m.

Correct Answer: A

Question 17 Explanation:

If we want to get distinct elements then we need to perform cross product in between the relations r₁,
r₂, …. r_m.