Bruce Momjian <pgman@candle.pha.pa.us> writes:
> Even if we could do it, we would be feeding clients attno
> values that are inaccurate, causing problems when attno is joined to
> other tables.
Good point; we'd need similar views replacing pg_attrdef and probably
other places. Messy indeed :-(
But as Dave already pointed out, it's probably pointless to worry.
The schema support in 7.3 will already de-facto break nearly every
client that inspects the system catalogs, so adding some more work
for DROP COLUMN support isn't going to make much difference.
regards, tom lane