フリー問題

問題文

A monitoring dashboard must warn when a standby would cost the business data at failover time. The team is choosing between two measurements the database publishes. Which pair does it need and why?

選択肢

1. The count of the sessions and the count of the applied transactions because the first bounds the data at risk and the second bounds the time before an open
2. The lag of what has arrived and the lag of what has been applied because the first bounds the data at risk and the second bounds the time before an open
3. The rate of the redo generation and the rate of the archived writes because the first bounds the data at risk and the second bounds the time to an open
4. The size of what has arrived and the size of what has been applied because the first bounds the data at risk and the second bounds the time to an open