ORA-28009: connection to sys should be as sysdba or sysoper

当我用下面命令导出时：
C:\Documents and Settings\z> exp sys/password@ora9　file= 'c:\exp.dmp '
full=y

遇到 ORACLE 错误 28009
ORA-28009: connection to sys should be as sysdba or sysoper
是因为sys不能导出数据库么？


------解决方法--------------------------------------------------------
sys不能用做EXP，导全库用system用户