Franz(dot)Rasper(at)izb(dot)de writes:
> Postgres 7.2.1 (Debian woody)
This bug has been fixed since 7.2.2 ...
2002-06-15 14:38 tgl
* src/backend/utils/adt/ruleutils.c (REL7_2_STABLE): Back-patch 7.3
fix to fully parenthesize UNION/EXCEPT/INTERSECT queries in
ruleutils output. The previous partial parenthesization was a hack
to get around grammar restrictions that have since been fixed; and
as Sam O'Connor pointed out, there were cases where it didn't work.
The 7.2 branch is no longer supported at all, but if you insist on using
it you should at least be running the latest point-release, 7.2.8.
Reasons why can be found on this and following pages:
http://developer.postgresql.org/docs/postgres/release-7-2-8.html
regards, tom lane