On Thu, 8 May 2003, Dennis Gearon wrote:
> it does a full scan of the table's child and parent columns upon
> creation of a foreign key?
It currently runs the trigger once per row in the referencing table.
Doing a single select with not exists will almost certainly be faster, but
that's waiting for someone else to decide to do it or me to get time to do
it. :)
Some form of check is required, AFAIK however, because if the constraint
isn't satisified at the end of the alter table an error should be thrown.