CREATE OR REPLACE FUNCTION uuid_or_null(str text)
           RETURNS uuid AS $$
           BEGIN
                 RETURN str::uuid;
           EXCEPTION WHEN invalid_text_representation THEN
                 RETURN NULL;
           END;
           $$ LANGUAGE plpgsql;
   
             SELECT DISTINCT "Id", "Person"
           FROM "Document"
           WHERE "Person" IS NOT NULL AND uuid_or_null("Person") IS NULL