フリー問題

問題文

A DBA wants one query that returns the current sessions of every instance of a four-instance Oracle RAC database, and wants to be able to narrow the result down to two of the instances afterwards. Which statement describes the views correctly?

選択肢

1. The global dynamic performance views return the rows of every qualified instance and carry an extra column that names the instance, so the same query can be narrowed down by filtering on that column.
2. The instance-specific dynamic performance views return the rows of every qualified instance and carry an extra column that names the instance, so the same query can be narrowed down by filtering on that column.
3. The global dynamic performance views return the rows of every qualified instance as one aggregated row per statistic, so the result cannot be narrowed down to a subset of the instances.
4. The global dynamic performance views need to be created by a script before they can be queried, and they return solely the rows of the instance that the session is connected to.