/*  두개중 편하신대로.. */
WITH T AS (
SELECT '001-010' DATA1 ,'1' DATA2 FROM DUAL UNION ALL
SELECT '001-010' ,'2' FROM DUAL UNION ALL
SELECT '001-010' ,'A' FROM DUAL 
)


SELECT MAX(TO_NUMBER(DATA2)) FROM T 
--WHERE REGEXP_LIKE(DATA2,'[1-9]')       
WHERE DATA2 >= '1' AND DATA2 <= '9'  

WITH t1 AS
(SELECT '1' AS v1 FROM dual UNION ALL
 SELECT '2'  FROM dual UNION ALL
 SELECT 'A'  FROM dual)
SELECT t2.v1
FROM (SELECT v1
            ,row_number() OVER (ORDER BY decode(regexp_replace(v1, '[A-Za-z]+', null), '', 0
                                                       , 1)||ASCII(v1) DESC) rn
        FROM t1) t2
WHERE rn = 1