Re: Deferrable constraint execution not respecting "initially immediate"?

On Mon, Jul 10, 2017 at 10:25 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> > From "CREATE TABLE":
> > "A constraint that is not deferrable will be checked immediately after
> > every command."
>
> > I think the above should be "after every row" instead of "after every
> > command".
>
> I believe that FK constraints work differently from indexes in this
> regard. Not sure that we want to get into that level of detail here.
>

​Since three of the 4 types are done "after every row" if we want to
simplify (I'm leaning toward being precise here) I'd rather be imprecise
about the FK.​ Pretending that a FK change is checked sooner than it
really is seems like a minor omission since the observed behavior isn't
likely to be noticeable. Wondering why "update pk = pk + 1" doesn't work
by default when PK constraints are checked "after every command" has been
shown to be noticeable.

David J.