Exercise 7.23 Assume a quad-core computer system can process database transactions at a steady state rate of requests per second. Also assume that each transaction takes, on average, a fi xed amount of time to process. The following table shows pairs of transaction latency and processing rate.

Average transaction latency Maximum transaction processing rate 1 ms 5000/sec 2 ms 5000/sec 1 ms 10,000/sec 2 ms 10,000/sec For each of the pairs in the table, answer the following questions:

7.23.1 [10] <7.11> On average, how many requests are being processed at any given instant?

7.23.2 [10] <7.11> If moved to an 8-core system, ideally, what will happen to the system throughput (i.e., how many transactions/second will the computer process)?

7.23.3 [10] <7.11> Discuss why we rarely obtain this kind of speed-up by simply increasing the number of cores.