Trying to delete the older of the duplicated pairs: # SELECT id, author, count(1), max(stamp) as maxx FROM pref_rep GROUP BY id, author HAVING count(1) >1 and stamp < maxx; ERROR: column "maxx" does not exist LINE 4: HAVING count(1) >1 and stamp < maxx; ^ On Mon, Feb 4, 2013 at 3:36 PM, Alexander Farber <alexander.farber@xxxxxxxxx> wrote: >>> http://stackoverflow.com/questions/14688523/adding-primary-key-table-contains-duplicated-values > -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general