Question

Database Structures

Question (50 points) . (10 points) Consider the join RDRa-Sb S, given the following information about the relations to be joined. Compute O costs for the following join operations. Relation R contains 4,000 tuples with blocking factor 40 .Relation S contains 2,000 tuples with blocking factor 40 Attribute a of relation R refers to attribute b of relation S Attribute b of relation S is the primary key for S Both relations are stored as simple heap files and 27 buffer caches (pages) are available. Each tuple in S matches with two tuples in R on average. a) (5 pts) What is the cost of joining R and S using a block nested loop join. b) (5 pts) the secondary index with index level 1 What is the cost of joining R and S using Index based nested loop join

Answer 1