75. Your test database is configured to run in NOARCHIVELOG mode. One of the data files in the USERS
tablespace is lost due to a media failure. You notice that all the online redo logs have been overwritten
since the last backup.
What would you do to recover the data file?
A.Take the USERS tablespace offline and re-create the lost data file.
B.Shut down the instance, restore the data file from the last consistent backup, and restart the database
instance.
C.Shut down the instance, restore all the database files from the last consistent backup, and restart the
database instance.
D.Take the USERS tablespace offline, restore all the data files of the USERS tablespace from the last
consistent backup, and make the tablespace online.
Answer: C
答案解析：
参考：http://blog.csdn.net/rlhua/article/details/12616383
在非归档模式下，只能使用冷备份来备份所有的文件，当数据文件丢失，重做日志被覆盖。则只能恢复到最近一次的一致性备份。不能用重做日志恢复到指定的时间点。
数据库处于NOARCHIVELOG模式（默认模式）时，只能恢复到最后一次备份时的状态。在该备份之后执行的所有事务处理都会丢失。