Thank you: that's exactly what I needed. > I think you want to use a full outer join with slightly unusual > bracketing: > > SELECT t.id, COALESCE(a.t,b.t) AS t, a.a, b.b > FROM tabid t LEFT JOIN ( > taba a FULL OUTER JOIN tabb b ON (a.id,a.t) = (b.id,b.t)) > ON t.id = COALESCE(a.id,b.id); > > This will start by doing the inner most thing first, join taba to tabb > matching rows where the id and timestamp is the same, then go on to > match these to tabid. The COALESCEs are needed because when either side > is missing their values will be NULL and hence we need to look at both. Passa a Yahoo! Mail. La webmail che ti offre GRATIS spazio illimitato, antispam e messenger integrato. http://it.mail.yahoo.com/ ; -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general