Answer by: Frank Bax
(http://article.gmane.org/gmane.comp.db.postgresql.sql/16284)

No, it's not "simple". You need to join the results of above sql back to the original table (and relocate the order by clause):

[sql]
SELECT notes.note_id, notes.user_id, maxx.max_date, notes.note
FROM (SELECT n.user_id, max(n.modified_date) AS max_date FROM notes n GROUP by n.user_id) AS maxx
JOIN notes on notes.user_id = maxx.user_id AND notes.modified_date = maxx.max_date
ORDER BY notes.user_id;
[/sql]