Multiple choice technology databases

deference between union and union all

  1. Union all will remove the duplicate rows from the result set while Union does'nt

  2. Union will remove the duplicate rows from the result set while Union all does'nt

  3. Both Union and Union all will remove duplicate rows from result set

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The UNION operator combines the results of two queries and removes duplicate rows, whereas UNION ALL combines the results and includes all duplicates, making UNION slower but cleaner.

Keep practicing — related questions