with 
base as (
select
    EMP_CODE as CODE
    ,EMP_LAST_NAME as SURNAME
    ,EMP_FIRST_NAME as NAME
    ,replace(EMP_LAST_NAME||EMP_FIRST_NAME," ","") as SORT_KEY
    ,count() over(partition by replace(EMP_LAST_NAME||EMP_FIRST_NAME," ","")) as cnt
from
    EMP
where
    VALID_FLG='1'
)
select
    CODE
    , SURNAME
    , NAME
from
    base
where
    2<=cnt
order by
    SORT_KEY
    ,CODE