WITH last_mod AS (
SELECT
sno
,Max(last_modified_date) last_modified_date
FROM uniq_select_records
GROUP BY sno
)
SELECT
u.sno
,u.item_name
,u.start_date
,u.end_date
,u.Action_flag
,u.last_modified_date
,u.creation_date
FROM uniq_select_records u
JOIN last_mod l
ON u.sno = l.sno
AND u.last_modified_date = l.last_modified_date)