Equality Joins With One Join Column
R S is a common operation. The cross product is too large. Hence, performing R S and then a selection is too inefficient.
Assume: M pages in R, pR tuples per page, N pages in S, pS tuples per page.
- In our examples, R is Person and S is Purchase.
Cost metric: # of I/Os. We will ignore output costs.
FROM Person R, Purchase S