Equality Joins With One Join Column

• In algebra: R S. Common! Must be carefully optimized. R S is large; so, R S followed by a selection is inefficient.

• Assume: M tuples in R, pR tuples per page, N tuples in S, pS tuples per page.

  • In our examples, R is Reserves and S is Sailors.

• Cost metric: # of I/Os. We will ignore output costs.

SELECT *

FROM Reserves R1, Sailors S1

WHERE R1.sid=S1.sid

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