Consider relations R$($a$,$ b$,$ c$),$ S$($a$,$ d$),$ and T$($a$,$ e$,$ f$)$ to be joined on the common attribute a$.$ Assume that there are no indexes available on the tables.

There are B $=445$ pages in the buffer

R spans M $=1,500$ pages with $80$ tuples per page

S spans N $=4,500$ pages with $150$ tuples per page

T spans O $=200$ pages with $250$ tuples per page

In computing the I$/$O cost$,$ you can assume the simplest cost model where pages are read and written one at a time. You can also assume that you will need one buffer block to hold the evolving output block and one input block to hold the current input block of the inner relation. You may ignore the cost of the writing of the final results.

Compute the I$/$O cost of the block nested loop join with S as the outer relation and R as the inner relation.

Question $5$ options:

$17500$

$18000$

$18500$

$19000$

$19500$

$20500$

$21000$