For strict security, you can disallow all access to underlying tables, and grant permissions to users or groups of users to execute certain stored procedures. This approach strictly defines who can define data in the database.
To allow users with the particular authorities to administer certain tasks using IQ system procedures:
Grant the authority to the designated group.
Grant EXECUTE permissions on the IQ procedure for performing the authority tasks to the group.
When you create a new user who is to be granted the authority, grant membership for this user to the group created for that authority. Since most authorities are inherited through group membership, the user inherits the authority and also the execute permissions for the IQ procedures from the group.