5. (9 pt) Suppose that we are using a disk system where the time to move the read/write head to a block is 15 ms, and the time for a block transfer is 0.4 ms. Suppose we want to compute a two-pass hash-join of R with S, and we have that B(R)=1000, B(S)=500, and M=101. To speed up the join, we want to use as few buckets as possible (assuming tuples distribute evenly among buckets), and read and write as many blocks as we can to consecutive positions on the disk. Answer the following questions: a) (1 pt) How many disk I/O's are required to perform this join operation? b) (5 pt) How long would it take to perform this operation if we use hybrid hash-join (as described in Example 15.9)? c) (3 pt) How long does a sort-based join take under the same conditions, assuming we write sorted sublists to consecutive blocks in disk