Chapter 15, Problem 5PE

Explanation of Solution

Lowest-cost way to compute r and s relations:

• The relation “r” is called the outer relation and “s” is called the inner relation of the join, since the loop for “r” encloses the loop for “s”.
• The user can store the whole smaller relation in memory, read the larger relation block by block and perform nested loop join using the larger one as the outer relation.
• The nested loop join algorithm is expensive, since it examines every pair of tuples in the two relations...

Explanation of Solution

Amount of memory required for this algorithm:

• The number of I/ O (Input/ Output) operations is equal to “b_r + b_s”, and memory requirement is “min (b_r + b_s) + 2” pages...