잠긴 계정에 대해 UNLOCK 수행 시 DBA_USERS의 LAST_LOGIN 컬럼이 업데이트 되는 현상

SQL> create user u5 identified by 'u5'; User 'U5' created. SQL> grant resource to u5; Granted. SQL> set time on 14:00:31 SQL> set timing on 14:00:37 SQL> col username for a20 14:00:53 SQL> col last_login for a20 14:01:44 SQL> select username, ACCOUNT_STATUS, LAST_LOGIN from dba_users where username = 'U5'; USERNAME ACCOUNT_STATUS LAST_LOGIN -------------------- ------------------------------ -------------------- U5 OPEN 1 row selected. Total elapsed time 00:00:00.000464 14:01:57 SQL> alter user u5 account lock; User 'U5' altered. Total elapsed time 00:00:00.009598 14:03:09 SQL> select username, ACCOUNT_STATUS, LAST_LOGIN from dba_users where username = 'U5'; USERNAME ACCOUNT_STATUS LAST_LOGIN -------------------- ------------------------------ -------------------- U5 LOCKED 1 row selected. Total elapsed time 00:00:00.000657 14:04:24 SQL> alter user u5 account unlock; User 'U5' altered. Total elapsed time 00:00:00.004211 14:04:31 SQL> select username, ACCOUNT_STATUS, LAST_LOGIN from dba_users where username ='U5'; USERNAME ACCOUNT_STATUS LAST_LOGIN -------------------- ------------------------------ -------------------- U5 OPEN 2025/02/26 14:04:31. 000000000 Asia/Seoul 1 row selected. Total elapsed time 00:00:00.000543