175.You are peer reviewing a fellow DBAs backup plan for his NOARCHIVELOG mode database, as shown here:
1、Put the tablespaces in backup mode.
2、Back up the datafiles for all tablespaces.
3、Take the tablespaces out of backup mode.
4、Back up all archived redo logs.
Your colleague asks for you to comment on his plan. Which response would be correct?
A. The plan will work as is.
B. The plan needs to be modified to allow for an archive-log switch after step 3.
C. The plan needs to be modified so that a backup of the archived redo logs occurs before step 1.
D. The plan needs to be adjusted to shut down the database after step 1 and to restart the database after step 2.
E. The plan cannot work as presented.
Answer: B，这是标准答案。正确答案应该是E

您同等地评估一位同行的 DBA 备份计划用于他的非归档记录模式数据库，如下所示：
1。将表空间置于备份模式。
2。备份所有表空间的数据文件。
3。将表空间带出备份模式。
4。备份所有归档重做日志。
你的同事要求你对他的计划发表评论。哪个响应是正确的？
B、该计划需要进行修改以允许第3步后存档日志切换。
E、计划不能像所呈列的那样工作

Since the database is in NOARCHIVELOG mode, the entire plan will not work since you can not perform hot backups in NOARCHIVELOG mode. If the database was in ARCHIVELOG mode, then you would choose option B. For more information, see Chapter 2, ―Performing Oracle User-Managed Backups.
由于数据库是在非归档记录模式下，整个计划将无法正常工作，因为你不能在非归档记录模式下执行热备份。如果数据库在归档记录模式下，那么你会选择选项B欲了解更多信息，请参阅第2章，“执行Oracle用户管理的备份。”

SQL> archive log list;
数据库日志模式             非存档模式
自动存档             禁用
存档终点            C:\Apps\Oracle\fast_recovery_area
最早的联机日志序列     83
当前日志序列           85
SQL> alter tablespace users begin backup;
alter tablespace users begin backup
*
第 1 行出现错误:
ORA-01123: 无法启动联机备份; 未启用介质恢复