Oracle Database provides several administrative user accounts that are associated with administrative privileges.
About Administrative User Accounts
Administrative user accounts have special privileges required to administer areas of the database, such as the CREATE ANY TABLE or ALTER SESSION privilege, or EXECUTE privilege on packages owned by the SYS schema.
SYS
When you create an Oracle database, the user SYS is automatically created with all the privileges.
SYSTEM
When you create an Oracle database, the user SYSTEM is also automatically created and granted the DBA role.
SYSBACKUP, SYSDG, SYSKM, and SYSRAC
When you create an Oracle database, the following users are automatically created to facilitate separation of duties for database administrators: SYSBACKUP, SYSDG, SYSKM, and SYSRAC.
The DBA Role
A predefined DBA role is automatically created with every Oracle Database installation. This role contains most database system privileges. Therefore, the DBA role should be granted only to actual database administrators.
