
In the old syntax, which used UNBOUNDED, we had a similar restriction, but commit d363d42bb9a4399a0207bd3b371c966e22e06bd3, which changed the syntax, eliminated it. Put it back. Patch by me, reviewed by Dean Rasheed. Discussion: http://postgr.es/m/CA+Tgmobs+pLPC27tS3gOpEAxAffHrq5w509cvkwTf9pF6cWYbg@mail.gmail.com