[ORA-12988] cannot drop column owned by sys 에러

/as sysdba 계정

'SYS'계정으로 만든 TABLE은 컬럼추가나 변경은

가능하지만 각 컬럼들은 삭제가 불가능하다.

ORA-12988: cannot drop column from table owned by SYS

Cause: An attempt was made to drop a column from a system table. Action: This action is not allowed

결론은 컬럼 삭제만 막아놓았다.(오라클에서)