正解:D,E,G
Roles and privileges in Oracle manage access and capabilities within the database:
* Option A: False. Roles are not "owned" in the traditional sense by the user who created them. They exist independently within the Oracle database and are assigned to users.
* Option B: False. System privileges can be very granular, affecting specific types of operations or database objects, not always the entire database.
* Option C: False. Roles are not owned by the SYS schema but are managed by database security and can be created by any user with sufficient privileges.
* Option D: True. A role can indeed contain a combination of several privileges, including other roles, allowing for flexible and layered security configurations.
* Option E: True. By default, a user has all object privileges for objects they own (i.e., objects in their schema).
* Option F: False. PUBLIC is a special designation that applies to all users; individual privileges granted to PUBLIC cannot be revoked from a single user without revoking them from all users.
* Option G: True. PUBLIC is a role granted by default to every user in an Oracle database, providing
* basic privileges necessary for general usability of the database.