問題文
A table has had many rows deleted over the years and full scans of it are still slow. An administrator plans an online shrink of the segment. What has to be true of the object and its tablespace before that can run?
選択肢
- The statistics of the object have to be current and the segment has to have been analyzed for chained rows within the last day.
- Row movement has to be enabled on the object and the segment has to live in a locally managed tablespace that uses automatic segment space management.
- The object has to be in read only mode and the segment has to have free space reserved above the current high water mark.
- The object has to be locked in exclusive mode and the segment has to live in a tablespace whose block size differs from the default.