創建表空間和用戶時，需要的時候竟然忘記了密碼，試了好多次都沒連接上，進而用戶也被鎖定，下面就教您處理Oracle默認用戶的密碼問題的方法，希望對和我一樣情況的朋友們有所幫助。
1.安裝時選擇的自動安裝，忘了用戶名和密碼導致現在試了幾個Oracle默認用戶名密碼後（表格中附帶默認用戶名及密碼），都提示無效的用戶名、密碼，
Username
Password
Description
See Also
CTXSYS
CTXSYS
The Oracle Text account
Oracle Text Reference
DBSNMP
DBSNMP
The account used by the Management Agent component of Oracle Enterprise Manager to monitor and manage the database
Oracle Enterprise Manager Grid Control Installation and Basic Configuration
LBACSYS
LBACSYS
The Oracle Label Security administrator account
Oracle Label Security Administrator's Guide
MDDATA
MDDATA
The schema used by Oracle Spatial for storing Geocoder and router data
Oracle Spatial User's Guide and Reference
MDSYS
MDSYS
The Oracle Spatial and Oracle interMedia Locator administrator account
Oracle Spatial User's Guide and Reference
DMSYS
DMSYS
The Oracle Data Mining account.
Oracle Data Mining Administrator's Guide
Oracle Data Mining Concepts
OLAPSYS
MANAGER
The account used to create OLAP metadata structures. It owns the OLAP Catalog (CWMLite).
Oracle OLAP Application Developer's Guide
ORDPLUGINS
ORDPLUGINS
The Oracle interMedia user. Plug-ins supplied by Oracle and third party format plug-ins are installed in this schema.
Oracle interMedia User's Guide
ORDSYS
ORDSYS
The Oracle interMedia administrator account
Oracle interMedia User's Guide
OUTLN
OUTLN
The account that supports plan stability. Plan stability enables you to maintain the same execution plans for the same SQL statements. OUTLN acts as a role to centrally manage metadata associated with stored outlines.
Oracle Database Performance Tuning Guide
SI_INFORMTN_SCHEMA
SI_INFORMTN_SCHEMA
The account that stores the information views for the SQL/MM Still Image Standard
Oracle interMedia User's Guide
SYS
CHANGE_ON_INSTALL
The account used to perform database administration tasks
Oracle Database Administrator's Guide
SYSMAN
CHANGE_ON_INSTALL
The account used to perform Oracle Enterprise Manager database administration tasks. Note that SYS and SYSTEM can also perform these tasks.
Oracle Enterprise Manager Grid Control Installation and Basic Configuration
SYSTEM
MANAGER
Another account used to perform database administration tasks.
Oracle Database Administrator's Guide
這時候要找到一組用戶名、密碼提示被鎖，才能進行下一步
安裝ORACLE時，若沒有爲下列用戶重設密碼，則其默認密碼如下：
用戶名/密碼
登錄身份
說明
sys/change_on_install
SYSDBA或SYSOPER
不能以NORMAL登錄，可作爲默認的系統管理員
system/manager
SYSDBA或NORMAL
不能以SYSOPER登錄，可作爲默認的系統管理員
sysman/oem_temp
sysman 爲oms的用戶名
scott/tiger
NORMAL
普通用戶
aqadm /aqadm
SYSDBA或NORMAL
高級隊列管理員
Dbsnmp/dbsnmp
SYSDBA或NORMAL
複製管理員
2.在CMD中啓動SQLPLUS；用sqlplus/as sysdba登錄，提示
連接到:
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
3. 執行ALTER USER 你被鎖的用戶名 ACCOUNT UNLOCK；
4. 重新用SQL/PLUS登錄，用你剛剛解鎖的用戶名、密碼；
重新修改密碼就可以了！
具體操作如下：
1.運行->sqlplus /nolog
2.輸入conn / as sysdba 管理員賬戶登錄
3.如果用戶被鎖定先解鎖：
alter user system account unlock;
4.修改密碼：
alter user system identified by wanglj;
接下來可以用sqlplus登陸了。