Multiple choice

In the Join of a relation P with a relation Q, P has 'm' tuples and Q has 'n' tuples. Then, the maximum and minimum sizes of the Join (respectively), are

  1. m + n and 0

  2. mn and 0

  3. m + n and |m - n|

  4. mn and m + n

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The maximum size is possible when every tuple of r is combined with every tuple of S to get mn tuples. The minimum size is possible when no tuple of R is able to combine with any tuple of S.