Oracle Database SQL — Question 218

Which two statements are true about a self join? (Choose two.)

Answer options

• A. It can be a left outer join.
• B. It must be an equijoin.
• C. It must be a full outer join.
• D. The join key column must have an index.
• E. It can be an inner join.

Correct answer: A, E

Explanation

A self join can be performed using various types of joins, including left outer joins and inner joins, which makes options A and E correct. However, it does not have to be an equijoin or full outer join, and there is no requirement for the join key column to have an index, making options B, C, and D incorrect.