प्रश्न:
SELECT table_id, series_id, revision_id, year
FROM tableName t INNER JOIN
(SELECT revision_id, max(year) AS year
FROM tableName
WHERE series_id = 2
GROUP BY revision_id) s
USING (revision_id, year)
WHERE series_id = 2;
परिणाम:
table_id | series_id | revision_id | year
----------+-----------+-------------+------
2 | 2 | 1 | 2009
4 | 2 | 2 | 2009
5 | 2 | 3 | 2010
(3 rows)