Question 8855 – Database-Management-System

Consider the following relations A, B, C.

How many tuples does the result of the following SQL query contain?

SELECT A.id 
FROM A 
WHERE A.age > ALL (SELECT B.age 
                   FROM B 
                   WHERE B. name = "arun")

Correct Answer: B

First query (2) will be executed and 0 (no) rows will be selected because in relation B there is no Name ‘Arun’.
The outer query (1) results the follow and that will be the result of entire query now. (Because inner query returns 0 rows).