In your test database， you have created the ORDERS table as an index-organized table （IOT）. To facilitate faster querying， you have created a mapping table and a bitmap index on the ORDER_FILLED column. You observe that the query performance degrees when users perform a large volume of transactions. While investigating the reason， you find that the mapping table segment is fragmented， leading to poor performance. Which option would you use to defragment the mapping table without affecting the original table data？（）

A. You find that one of the redo log members in each redo log group is lost.
B. You find that a data file that belongs to the USERS tablespace is damaged.
C. You find that a data file that belongs to the SYSTEM tablespace is damaged.
D. You find that the current redo log group is damaged and is not available for recovery.
E. You realized while performing a recovery that an archived redo log file needed for recovery is lost.

A. The subplan must belong to the consumer group， SYS_GROUP.
B. The total CPU usage at any given level must be less than 100%.
C. The subplans can be used to restrict the degree of parallelism for a user.
D. You can use a resource plan instead of a consumer group to implement a priority ranking within the plan.

A. This operation resets the SCN for the database.
B. This operation creates a new incarnation of the database.
C. This operation moves all the redo log files to a different location.
D. This operation deletes the old redo log files and creates new redo log files.
E. This operation updates all current datafiles and online redo logs and all subsequent archived redo logs with a new RESETLOGS SCN and time stamp.