Rob Mosher <mosher(at)andrews(dot)edu> writes:
> Is there anyway I can change a field to allowing nulls without dumping
> the table, dropping it, recreating it as desired, and filling all the
> data back in?
ALTER TABLE ... DROP NOT NULL does the trick in recent releases. Before
that, you could resort to manually poking the attnotnull flag in
the pg_attribute row for the field.
regards, tom lane