After installing the database for a long time we do not often forget their passwords, in that case not quick to reload the database, you can modify the order of their methods.
One: Forget sys, system user's password
1, the start menu click 'Run', type 'cmd', open a command prompt window, enter the following command: orapwd file = E: \ oracle \ database \ pwdctcsys.ora password = 123456 this command to re-generate the database password file. In the ORACLE_HOME directory \ at the location of the password file database directory. The password (123456) is to modify the sys user password.
2,sqlplus / as sysdba
3,alter user sys identified by password
Two: Forget SYS user, or the SYSTEM user's password
1, access to the database, sqlplus / as sysdba
2, if the SYSTEM user's password is forgotten, you can use the SYS user login , and then change the password using ALTER USER command.
2-1，CONN SYS/PASS_WORD AS SYSDBA;
ALTER USER SYSTEM IDENTIFIED BY "newpass";
3. If the SYS user's password is forgotten, you can use SYSTEM logged-on user, and then modify the password using the ALTER USER command.
3-1，CONN SYSTEM/PASS_WORD ;
ALTER USER SYSTEM IDENTIFIED BY "newpass";
Three: Forget the user in addition to SYS, SYSTEM user login password
1 with SYS (or SYSTEM) login user
2, CONN SYS / PASS_WORD AS SYSDBA ;
using the user's password to modify the following statement: ALTER USER user_name IDENTIFIED BY "newpass ";
Log on as oracle, there are three: normal sysdba common identity system administrator sysoper system operator identity