On Wed, 30 Aug 2000, Jie Liang wrote:
> Hi,
>
> I knew that if no constarint, it populate very quick, my question is:
> when two tables have been
> reloaded, then I want to add a foreign key constraint to it, say:
> tableA has primary key column (id)
> tableB has a column (id) references it, so I say:
> ALTER TABLE tableB ADD CONSTRAINT distfk FOREIGN KEY (id) REFERENCES
> tableA(id) ON DELETE CASCADE ;
Yeah, the alter table has to check that the constraint is valid. There
might be a faster way than the current "scan through table calling
trigger function" mechanism, although doing most of them starts pulling
logic for the obeying constraint into multiple places.
