文档解释
ORA-16177: media recovery is not required
Cause: The THROUGH LAST SWITCHOVER clause of the ALTER DATABASE RECOVER MANAGED STANDBY DATABASE was specified and the database has been recovered to the most recent End-Of-Redo marker. All known archived logs have been applied. Managed recovery is not required.
Action: No action is necessary. The standby database may be activated as a new primary or may continue as a standby.
ORA-16177：表明Media Recovery不在本次recovery操作的必要范围内。
官方解释
ORA-16177 is a generic error message. It means that Media Recovery is not required for the current recovery operation.
常见案例
此错误通常是在有空洞发生时发出警告。空洞是大小为0的日志文件块，其大小大于一个数据块。当恢复某个文件时，如果发现有空洞，就会出现此错误。
一般处理方法及步骤
1.确定文件中存在空洞；
2.根据需要进行media recovery操作，或者使用skip option跳过空洞；
3.忽略此警告，继续恢复文件；
4.如果文件恢复完成而空洞未被一同恢复，那么只需要对空洞重新进行恢复；
5.在进行新的恢复操作前，一定要检查是否有空洞；
6.确保文件在正常恢复前通过分析正确恢复。
