To see if they are try :
SELECT
relname,
attname
FROM
pg_attribute AS pa
JOIN pg_class AS pc ON pa.attrelid = pc.oid
WHERE
atttypid = 'oid'::regtype
AND relnamespace = 'public'::regnamespace
AND attnum > 0;
Where relnamespace is the schema you are interested in.
pg_dump which throws error is called with -n public -n firma74 parameters
I tried
relname,
attname
FROM
pg_attribute AS pa
JOIN pg_class AS pc ON pa.attrelid = pc.oid
WHERE
atttypid = 'oid'::regtype
AND relnamespace in ( 'public'::regnamespace, 'firma74'::regnamespace )
AND attnum > 0;
It returs 0 rows.
Andrus.