The following bug has been logged online:
Bug reference: 2097
Logged by: Evan Carroll
Email address: personal@evancarroll.com
PostgreSQL version: 8.1
Operating system: Linux -- Debian & Ubuntu.
Description: Union bug.
Details:
There apears to be a bug with the Union feature in 8.1. If nothing else it
is an oddity to be recognized. The naming from the result table seems to be
from the first select of the union but it only accepts the second column to
be named identically and misleadingly to the first.
"select col1 as x col1 from tab1 union select * from tab2' and it selects
the first and second column from both tables
IE Here is the exact querry
select fkey_event as F, fkey_event from event_contact UNION select * from
event_object ORDER BY fkey_event;
and here is the header from the outputted table
f | fkey_event
-----+------------
But yet the rows are not the same, they correspond to the natural order of
the sql union, where f is the first col of tbl1+ tbl2, and fkey_event is the
second column of tbl1+tbl2.