If relation R and relation S are both 32 pages and round-robin partition over 2 machines with 4 buffer pages each, what is the network cost (number of bytes sent over the network by any machine) for performing a sort-merge join in the worst case

224

Explanation:

There's need for us to read the data from disk after which we now stream the data to the appropriate machine, the machine will then performs a sort-merge join between two 16page relations with 4 buffer pages.

So, this Will be = (1 + 6) * (16 + 16) = 224 I/Os per machine.