오라클 system 계정이 락걸렸을 때

cmd에 차례대로 입력

1. 비밀번호 변경

C:>sqlplus "/as sysdba"
SQL>show user
USER is "SYS"

C:\Users\user>sqlplus "/as sysdba"
SQL*PLUS: Realease ...
Copyright (c) 1982, 2014, Oracle ...

SQL>show user
USER is "SYS"

SQL>alter user system identified by 지정할 비밀번호;
User altered.

2. 락 해제

SQL>alter user system account unlock;
User altered.