MySQL 5.6

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CREATE TABLE myTable (
  ds_id INTEGER,
  Clm_due INTEGER,
  Review VARCHAR(1)
);

INSERT INTO myTable
  (ds_id, Clm_due)
VALUES
  ('4556', '200'),
  ('4556', '200'),
  ('4556', '200'),
  ('5555', '500'),
  ('5555', '500'),
  ('5555', '100'),
  ('6666', '20'),
  ('6666', '20'),
  ('6666', '600');

update myTable m inner join (
  select ds_id, sum(Clm_due) total
  from myTable
  group by ds_id
) t on t.ds_id = m.ds_id
set Review = 'X' 
where t.total < 1000
select * from myTable


ds_id
Clm_due
Review


4556
200
X

4556
200
X

4556
200
X

5555
500
null

5555
500
null

5555
100
null

6666
20
X

6666
20
X

6666
600
X

ds_id	Clm_due	Review
4556	200	X
4556	200	X
4556	200	X
5555	500	null
5555	500	null
5555	100	null
6666	20	X
6666	20	X
6666	600	X