Oracle Database Administration I — Question 35

Which statement is true about the INTERSECT operator used in compound queries?

Answer options

• A. Multiple INTERSECT operators are not possible in the same SQL statement
• B. It processes NULLs in the selected columns
• C. INTERSECT is of lower precedence than UNION or UNION ALL
• D. It ignores NULLs

Correct answer: B

Explanation

The correct answer is B because the INTERSECT operator indeed processes NULL values present in the selected columns, including them in the result set if they are part of the intersection. Option A is incorrect because multiple INTERSECT operators can be used in the same query. Option C is wrong as INTERSECT has higher precedence than UNION or UNION ALL, and option D is also incorrect since INTERSECT does not ignore NULLs.