Re: Cascade Trigger Not Firing

At the very least that note about this behavior should be highlighted,
probably on the Trigger Behavior page and not buried in a bunch of notes on
the Create Trigger page.

On Fri, Sep 13, 2019 at 4:03 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Judy Loomis <hoodie(dot)judy(at)gmail(dot)com> writes:
> > I'm going to have to really look at all my BEFORE UPDATE triggers and
> make
> > sure we're not missing any more.
> > And I have to stop telling management that a trigger means we always know
> > when a value changes.
>
> Well, you can rely on that, just not like this. Use an AFTER trigger
> (else, you can't be sure it fires after all the BEFORE triggers)
> and instead of triggering it with a column parameter, have it do
> something like "if old.col is distinct from new.col".
>
> Yeah, it's a bit slower that way, but there's no free lunch,
> especially if you don't trust your other triggers. (Although,
> if you have so many triggers that that's a problem, I think you
> might have some other design issues.)
>
> regards, tom lane
>

--

----------------------------------------------------------
*Judy Loomis*
469.235.5839