You say you're logged in as "root". Did you mean on the system as well? Or are you logged in as "root" only in the database?
One possible reason:
You don't have write permissions to the /usr/etc/ directory. Try this:
select * INTO OUTFILE '/tmp/ReferralAuth.txt'
FIELDS Terminated BY ';' Lines Terminated by '\n' from ehpadmin.referral_Authorization
(normally every Linux use has write permissions to /tmp)
If it still does not work, check this page
for possible reasons for "access denied".