ready to return results to the user making the request.
The results are returned to the user at step (5).
Response time inside the computer is measured from the length of time it takes for steps
(2), (3), and (4) to execute. On the average response, time is typically between 1 and 2
seconds. Given all the computer had to go through, it is amazing that response time is as
fast as it is.
Fig. 11.1.5 shows how response time is measured.
Fig. 11.1.5 Measuring response time.Far and away, the biggest element of response time (i.e., steps (2), (3), and (4)) is the
amount of time needed to search for and retrieve data. The processing inside the
computer—steps (2) and (4)—occurs very quickly. It is step (3) that chews up the most
amount of time.
There is a term for step (3). That term is an “I/O” operation (or an “input/output”
operation). An I/O refers to the work done by the system in making either an input or an
output to the database managed by the system.
Fig. 11.1.6 depicts an I/O operation.
Chapter 11.1: Operational Analytics: Response Time