Thank you - On Mon, Feb 4, 2013 at 5:06 PM, Andreas Kretschmer <akretschmer@xxxxxxxxxxxxx> wrote: >> # alter table pref_rep add primary key(id, author); >> NOTICE: ALTER TABLE / ADD PRIMARY KEY will create implicit index >> "pref_rep_pkey" for table "pref_rep" >> ERROR: could not create unique index "pref_rep_pkey" >> DETAIL: Table contains duplicated values. how do you get this DETAIL, is it a setting for psql prompt? I've got a nice answer for my question at Stackoverflow: DELETE FROM pref_rep p USING ( SELECT id, author, max(stamp) stamp FROM pref_rep GROUP BY id, author HAVING count(1) > 1) AS f WHERE p.id=f.id AND p.author=f.author AND p.stamp<f.stamp; and learnt about SQL Fiddle too - http://sqlfiddle.com/#!11/59fbc/11 Regards Alex -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general