Recovering NOLOGGING Tables and Indexes

在使用CREATE TABLE AS SELECT创建表及索引时可以使用NOLOGGING选项，这将导致表或索引无法恢复
使用NOLOGGING操作后最好备份一下
NOLOGGING对象在恢复后会标识为逻辑错误，只能重建
Be aware that when you perform media recovery, and some tables or indexes are created normally whereas others are created with the NOLOGGING option, 
the NOLOGGING objects are marked logically corrupt by the RECOVER operation. 
Any attempt to access the unrecoverable objects returns an ORA-01578 error message. 
Drop the NOLOGGING objects and re-create them if needed.

Note: Because it is possible to create a table with the NOLOGGING option and then create an index with the LOGGING option on that table, 
the index is not marked as logically corrupt after you perform media recovery. 
The table was unrecoverable (and thus marked as corrupt after recovery), however, so the index points to corrupt blocks. 
The index must be dropped, and the table and index must be re-created if necessary.

另外在使用传输表空间后，也应该对相关表空间进行备份