Tom Lane wrote:
>
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> >> ERROR: ALTER TABLE / DROP CONSTRAINT is not implemented
>
> > I thought that was going in. According to Marc, if it sufficiently
> > warned users, and required them to type it twice, it would do Peter's
> > alter table code. Perhaps Peter decided to wait for 7.1?
>
> I thought the rest of us beat him up until he took it out ;-)
>
Was'nt that DROP COLUMN ?
Is'nt DROP CONSTRAINT something completely different ?
AFAIK constraints are not (should not;) be implemented as extra columns,
even though they look like it in CREATE TABLE clause.
So removing them would actually mean deleting some rows from some system
table(s). And you don't even have to check the validity of existing data as
have to when doing ADD CONSTRAINT.
----------------
Hannu