MySQL Obtenha as últimas linhas duplicadas
SELECT
t1.primary_id,
t1.duplicate_id,
t1.data1,
t1.data2
FROM
table_name t1
LEFT JOIN table_name t2
ON (t1.duplicate_id = t2.duplicate_id AND t1.primary_id < t2.primary_id)
WHERE
t2.primary_id IS NULL
MatrixZA