在测试库上insert一张大表，报undo不够，加上空间不够，就像flashback回去，但shutdown immediate的时候又不想等那么长的时间，就abort了。结果发现：
ORA-38760: This database instance failed to turn on flashback database
以下是解决方法：
[@more@]1.先flashback：
SQL> FLASHBACK DATABASE TO RESTORE POINT WMOS_GOLD_COPY;
Flashback complete.
2.SQL> alter database flashback off;
Database altered.
3.SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-38760: This database instance failed to turn on flashback database
4.SQL> SQL> FLASHBACK DATABASE TO RESTORE POINT WMOS_GOLD_COPY;
Flashback complete.
5.SQL> alter database open;
Database altered.