QUESTION NO: 170 
What methods of point-in-time recovery are available? (Choose all that apply.)
A. Change-based  
B. Cancel-based  
C. Time-based  
D. Sequence number-based  
E. Transaction number-based
Answer: A,B,C,D
时间点的恢复方法有哪些? 
A. Change-based基于更改 
B. Cancel-based基于取消 
C. Time-based基于时间 
D. Sequence number-based基于序列号
Change-based application allows you to recover the database to a specific SCN. Cancel-based recovery 
provides the ability for you to cancel recovery after each archived redo log application. Time-based 
recovery provides the ability to recover the database up to a specific point in time. Sequence number– 
based recovery allows you to recover the database up to a specific log sequence number.
原文:http://blog.csdn.net/xuejiayue1105/article/details/48949835