Answer:
a) 5 runs will be generated.
b) Since the buffer can hold 3 records, the first 3 runs are (1, 10, 11), (1, 5, 90) and (2, 10). Then we need to reserve one block as output buffer, the algorithm can merge two runs at most at the same time. As a result, we can choose to merge the first two runs into a larger one: (1,1,5,10,11,90), which is merged with the run (2, 10) to generate the final output.
Explanation:
5 runs will be generated.
Since the buffer can hold 3 records, the first 3 runs are (1, 10, 11), (1, 5, 90) and (2, 10). Then we need to reserve one block as output buffer, the algorithm can merge two runs at most at the same time. As a result, we can choose to merge the first two runs into a larger one: (1,1,5,10,11,90), which is merged with the run (2, 10) to generate the final output.
