63.Which method would you use to undo the changes made by a particular transaction without affecting the changes made by other transactions?
A. point-in-time recovery
B. execute the ROLLBACK command with transaction number
C. flashback the database to before the transaction was committed
D. determine all the necessary undo SQL statements from FLASHBACK_TRANSACTION_QUERY and use them for recovery
Answer: D
你会用哪一种方法撤消由一个特定的交易所做的更改,而不影响其他交易产生的变化?
D、从闪回事务查询确定所有必要的撤销SQL语句,并使用它们用于恢复
使用闪回查询功能,可以执行截止到特定时间的查询。使用SELECT语句的AS OF子句,可以指定要查看其对应数据的时间戳。这在分析数据差异时非常有用。
注:TIMESTAMP和SCN是AS OF子句的有效选项。
来自 “ ITPUB博客 ” ,链接:https://blog.itpub.net/81227/viewspace-2123439/
,如需转载,请注明出处,否则将追究法律责任。