WITH FIXED_EMP AS (
    SELECT
        EMP_CODE
        ,EMP_LAST_NAME
        ,EMP_FIRST_NAME
        ,REPLACE(EMP_LAST_NAME,' ','') || REPLACE(EMP_FIRST_NAME,' ','') AS FULL_NAME
    FROM EMP
    WHERE VALID_FLG = '1'  
),
DUP_COUNT AS (
    SELECT
        FULL_NAME
        ,COUNT(EMP_CODE) AS NAME_COUNT
    FROM FIXED_EMP
    GROUP BY FULL_NAME
)
SELECT
    fe.EMP_CODE AS CODE
    ,fe.EMP_LAST_NAME AS SURNAME
    ,fe.EMP_FIRST_NAME AS NAME
FROM FIXED_EMP fe
LEFT OUTER JOIN DUP_COUNT dc
    ON fe.FULL_NAME = dc.FULL_NAME
WHERE 1 < dc.NAME_COUNT
ORDER BY
    fe.FULL_NAME
    ,fe.EMP_CODE;