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DELETE FROM table_name
WHERE id NOT IN (SELECT max(t2.id)
                 from table_name t2
                 group by column_1, column_2, ...)

DELETE FROM table_name d
USING (
     SELECT min(id) as min_id, column_1, column_2 ...
     FROM table_name
     GROUP BY column_1, column_2 ...
) keep
WHERE (keep.column_1, keep.column_2, ...) = (d.column_1, d.column_2, ...)
  AND keep.min_id <> d.id

DELETE FROM table_name a
WHERE EXISTS (SELECT 1
              FROM  table_name b
              WHERE (a.column_1, a.column_2, ...) = (b.column_1, b.column_2, ...)
                AND b.id > a.id);

test=*# select * from maco1 ;
 id
----
  1
  1
  1
  1
  1
  2
  2
  2
  2
  2
  3
  3
  3
  3
(14 rows)
test=*# with keep as (select distinct on(id) id, ctid from maco1 ) delete from maco1 where ctid not in (select  ctid from keep);
DELETE 11
test=*# select * from maco1 ;
 id
----
  1
  2
  3
(3 rows)

test=*#