問題文
A DBA has to make the whole database able to be rewound to a point in the recent past. Which statement describes what has to be in place before that becomes possible?
選択肢
- The database has to keep a second copy of every data file, because the rewind switches to that copy and the target for how far back it reaches is decided when the copy is created.
- The database has to archive its logs and has to have a recovery area, because the images that the rewind reads are written into that area and the target for how far back it reaches is set as a parameter.
- The database has to run without archiving its logs, because the rewind reads the online logs alone and the target for how far back it reaches is limited by the size.
- The database has to archive its logs and has to have a recovery area, because the rewind reads the archived logs backwards and the target for how far back it reaches is taken from the retention policy of those backups.