Data Dictionary tables can be accessed only by users who have the required privileges to the tables. Access to the tables is strictly controlled to ensure that users (including system administrators) cannot modify them.
For sites that use Teradata Secure Zones, SELECT privilege on DBQL tables is revoked from PUBLIC. Users can access DBQL table information only through DBC.QryLog* views. This prevents zone users from accessing information not related to their zones. For more details, see Teradata Secure Zone Views.
Zone users can see the information for objects in their zone in DBC views, but they cannot see the information for any objects outside their zone. If a non-zone user needs to see information for all of the zones, grant ZONE OVERRIDE privilege to the user. Users with ZONE OVERRIDE privilege can see information from all zones. You can also grant SELECT privilege on a specific view, but users with SELECT privileges on a view obtain different result sets, depending on their zone membership or non-zone status. See GRANT ZONE OVERRIDE and REVOKE ZONE OVERRIDE in Teradata Vantage™ - SQL Data Control Language, B035-1149.