1. (10 points) Consider the following information regarding two relations R and S. -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 a of relation S Attribute a 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) Compute l/O costs for the following join operations using a block nested loop join b) (5 pts) Assume that the attribute R.a has the secondary Index with index level 2 and the attribute S.a has the secondary index with index level1 Compute I/O costs for the following join operations using a Index based nested loop join