如何区分哪些用户是ORACLE系统提供的?

有些时候，我们要清理数据库时，想把数据库中所有非系统自带的用户全部删除，在12C以前，我们只能通过人肉的方式，从12C 开始，多了一个字段： ORACLE_MAINTAINED如果时系统自带的，该值为Y,否则为N
就很好办了，直接使用以下语句就可以找出系统自带的用户了。


select username,account_status,
ORACLE_MAINTAINED from dba_users where ORACLE_MAINTAINED='Y';

SQL> r
1* SELECT username,account_status from dba_users where ORACLE_MAINTAINED='Y'

USERNAME ACCOUNT_STATUS

------------------------------
--------------------------------
SYS OPEN
SYSTEM OPEN
XS$NULL EXPIRED & LOCKED
OJVMSYS LOCKED
LBACSYS LOCKED
OUTLN LOCKED
SYS$UMF LOCKED
DBSNMP LOCKED
APPQOSSYS LOCKED
DBSFWUSER LOCKED
GGSYS LOCKED
ANONYMOUS EXPIRED & LOCKED
CTXSYS EXPIRED & LOCKED
DVF LOCKED
DVSYS LOCKED
GSMADMIN_INTERNAL LOCKED
MDSYS LOCKED
OLAPSYS LOCKED
XDB LOCKED
WMSYS LOCKED
GSMCATUSER LOCKED
MDDATA LOCKED
REMOTE_SCHEDULER_AGENT LOCKED
SYSBACKUP LOCKED
GSMUSER LOCKED
GSMROOTUSER LOCKED
SYSRAC LOCKED
SI_INFORMTN_SCHEMA LOCKED
AUDSYS LOCKED
DIP LOCKED
ORDPLUGINS LOCKED
ORDDATA LOCKED
SYSKM LOCKED
ORACLE_OCM LOCKED
ORDSYS LOCKED
SYSDG LOCKED

36 rows selected.