問題文
A team wants a single number that expresses how much work the whole instance is doing, so that separate components can be compared on one scale. Which description of database time is correct?
選択肢
- It counts the seconds that a user session spends idle at the client while it waits for the next request.
- It adds up the elapsed time of the background processes that have run since the last snapshot reached the repository.
- It measures the wall clock interval that lies between the two snapshots that a report was built from.
- It sums the processor time and the wait time outside the Idle class for every foreground session that has run since the instance started.