Databases often use fixed-length record files to speed indexed access to information
in its tables.
6.16 How would you expect process scheduling policies to be different on batch computing systems and
interactive systems?
Interactive computer systems like Unix and Windows use scheduling policies that share the computer
in some ???fair??? way among the concurrent users. This means some variation of round robin or
time-slice scheduling, perhaps mixed with additional policies for background, non-interactive processing.
Batch computer systems will use scheduling policies that in some way maximize the number of jobs
accomplished per hour or day. There is no moment-to-moment concern with fairness, but there is
still pressure to be as efficient as possible. Perhaps a FCFS or SRJF policy will be used, or a policy
that queues waiting jobs by priority.
6.17 How would you measure the success of a batch operating system? Would you measure the success of
an interactive system like Unix or Windows the same way? If not, how would you measure the success
of an interactive operating system?
Batch operating systems are often measured by the average number of jobs they complete per hour,
or by average CPU utilization.
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