問題文
A weekly task cannot run safely while ordinary sessions are changing data, and closing the database and opening it again with access limited is ruled out. Which statement about the state that fits this need is correct?
選択肢
- The reads and the writes aimed at the data files and the control files are halted while the statements of every DBA account keep running, so the task is able to change data at a moment when the other sessions are not able to.
- The statements issued by every account that holds the DBA role that the database supplies go on being accepted while the listener turns the arriving sessions away, so a session that has nothing in flight is not given an answer and is closed.
- The statements issued by SYS and by SYSTEM go on being accepted while the resource plan holds every other session back, so a session that has nothing in flight is not able to become busy again until the state is lifted.
- The sessions that are busy are ended at the moment the request arrives and every account that was connected has to sign in again, so the task begins with a database that has not a single other session left upon it.