[oracle] How To Recover a Lost Password on Oracle

#sqlplus /nolog
SQL>conn / as sysdba
SQL>alter user Username identified by PASSWORD;

To reset your Oracle database password, the process is a bit different. Your password file should be under \database\PWD.ora.
Delete it and run the Oracle password utility from the command prompt:
c\:Oracle\ora92\database>ORAPWD file=PWD.ora password={password} entries={however many}.
The is your new sys password. After you log in as sys, you can change it and create new passwords for the system.
reference: https://ccm.net/faq/4399-oracle-recover-lost-passwords