文档解释
ORA-12487: clearance labels not between DBHIGH and DBLOW
Cause: You attempted to enter a value for a clearance label that was not dominated by DBHIGH or did not dominate DBLOW.
Action: Enter clearance label values between DBHIGH and DBLOW.
ORA-12487错误提示:清除标签不在DBHIGH和DBLOW之间;