WITH TMP AS (
 SELECT * FROM HEALTH_CHECKUP a
 where not exists (select 1 from HEALTH_CHECKUP b 
 where a.member_code=b.member_code and a.checkup_date<b.checkup_date )
),
TMP2 AS(
select 
CHECKUP_DATE,
WEIGHT*10 - 10*lag(WEIGHT) over (partition by MEMBER_CODE order by CHECKUP_DATE)  r
,MEMBER_CODE 
from
HEALTH_CHECKUP a
)
SELECT tmp2.CHECKUP_DATE CK_DATE, TMP2.MEMBER_CODE CODE,LAST_NAME||FIRST_NAME NAME,
r/10 CHG_WT FROM TMP2
left join MEMBER_MST on TMP2.member_code = member_MST.member_code 
inner join tmp on tmp.member_code=tmp2.member_code
where abs(r)>=50
order by CHG_WT desc