Обсуждение: Adding ON UPDATE CASCADE to an existing foreign key constraint

I have a foreign key constraint that I'd like to alter. I'd rather not
drop and re-create it due to the size of the table involved. All I need
to do is add an ON UPDATE CASCADE.

Is it ok to set confupdtype to 'c' in pg_constraint (and will this be
all that's needed) or is it safer to drop and recreate the constraint?

PG Version 8.0.3


Thanks a lot


   - Rich Doughty

On Thu, 4 May 2006, Rich Doughty wrote:

> I have a foreign key constraint that I'd like to alter. I'd rather not
> drop and re-create it due to the size of the table involved. All I need
> to do is add an ON UPDATE CASCADE.
>
> Is it ok to set confupdtype to 'c' in pg_constraint (and will this be
> all that's needed) or is it safer to drop and recreate the constraint?

I don't think that's going to work, you'd probably need to change the
function associated with the trigger involved too.  It's probably safer to
do the drop and create.

Stephan Szabo wrote:
> On Thu, 4 May 2006, Rich Doughty wrote:
>
>
>>I have a foreign key constraint that I'd like to alter. I'd rather not
>>drop and re-create it due to the size of the table involved. All I need
>>to do is add an ON UPDATE CASCADE.
>>
>>Is it ok to set confupdtype to 'c' in pg_constraint (and will this be
>>all that's needed) or is it safer to drop and recreate the constraint?
>
>
> I don't think that's going to work, you'd probably need to change the
> function associated with the trigger involved too.  It's probably safer to
> do the drop and create.

ok, thanks.

--

   - Rich Doughty