> > How can we drop a column from a table ?
>
> It seems we can't.
The SQL command ALTER TABLE DROP COLUMN isn't supported; see
http://www.ca.postgresql.org/docs/faq-english.html#4.5
for a work-around; note that I dimly recall some caveats regarding
using this workaround, so tread lightly (back everything up first, and
test the results thoroughly afterwards).
Eric Lawson