Passwords for all Oracle system administration accounts except SYS, SYSTEM, and DBSMP are revoked after installation. Before you use a locked account, you must unlock it and reset its password.

If you created a preconfigured database during the installation, but you did not unlock accounts required to use the database, then you must unlock and reset those accounts using these procedures.

• Requirements for Database Passwords
  To secure your database, use passwords that satisfy the Oracle recommended password requirements, even the passwords for predefined user accounts.
• Oracle Database System Privileges Accounts and Passwords
  Review these system privileges accounts after installation in preparation for unlocking accounts and changing passwords.
• Guidelines for Changing System Privileges Account Passwords
  Follow these rules for changing Oracle Database system privileges account passwords.
• Locking and Unlocking User Accounts
  You can use Oracle Enterprise Manager Database Express (EM Express) to lock and unlock user accounts.
• Using SQL*Plus to Unlock Accounts and Reset Passwords
  Use this SQL*Plus procedure to unlock and reset user account passwords.