select 
    h.checkup_date as CK_DATE,
    h.member_code as CODE,
    m.last_name||m.first_name as NAME,
    h.chg_wt as CHG_WT
from (
    select
        checkup_date,
        member_code,
        round(weight - lead(weight)over(partition by member_code order by checkup_date desc), 1) as chg_wt,
        rank()over(partition by member_code order by checkup_date desc) as rnk
    from
        health_checkup
) h 
join 
    member_mst m
    on h.member_code = m.member_code
    and h.rnk = 1
    and abs(chg_wt) >= 5
order by 
    h.chg_wt desc,
    h.member_code desc