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Unformatted text preview: Merge-Sort. What is the minimum size of the main memory? Problem 3 : Query Optimization (30 points) The query processor is about to decide how to execute the following query on relations R(A,B) and S(B,C): SELECT * FROM R,S WHERE R.B=S.B AND S.B = 10 The following two plans are being considered: Plan 1 Plan 2 (1.2) (2.3) (1.1) (2.1) (2.2) " R . B = 10 S R . B = 10 S . B = 10 R R S Relation R has 60,000 tuples with 10 tuples per disk block and V(R,B)=12. Similarly, S has 30,000 tuples with 30 tuples per disk block and V(S,B)=5. Consider a model that estimates the cost of a query plan through the total number of intermediate and final tuples produced by the operators. (1) What are the sizes (number of tuples) of the intermediate results and final results under each plan? (2) What are the corresponding costs of plans 1 and 2? Which is the better plan?...
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This note was uploaded on 04/13/2010 for the course CSE 671 taught by Professor Hakanferhatosmanoglu during the Winter '06 term at Ohio State.
- Winter '06