INSERT INTO test_1 (id, test_class, test_method, old_ids)
SELECT
ss.id,
ss.test_class,
ss.test_method,
array_agg(old_id) old_id
FROM (SELECT
tm.id id,
tm.test_class test_class,
tm.test_method test_method,
t.id old_id
FROM (SELECT
min(id) id,
test_class,
test_method
FROM test
GROUP BY test_class, test_method
ORDER BY min(id)) tm
INNER JOIN test t
ON (t.test_class = tm.test_class AND
t.test_method = tm.test_method)) ss
GROUP BY ss.id, ss.test_class, ss.test_method;