To perform many of the administrative duties for a database, you must be able to execute operating system commands.
Depending on the operating system on which Oracle Database is running, you might need an operating system account or ID to gain access to the operating system. If so, your operating system account might require operating system privileges or access rights that other database users do not require (for example, to perform Oracle Database software installation). Although you do not need the Oracle Database files to be stored in your account, you should have access to them.
Administrative User Accounts
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.
