Re: Expanding HOT updates for expression and partial indexes

On Mon, 2026-03-16 at 16:51 -0400, Greg Burd wrote:
> > Also, the "actually changed values" is only valid for a single
> > tuple,
> > and it would be good to clarify that and make sure there's not a
> > lot of
> > room for confusion there.
>
> Yes, that's true... too much confusion and not enough juice for the
> squeeze.  I'm dropping that.

That is an interesting case you found in that the columns targeted by
an update are not a superset of the columns with actually changed
values. But I'm not sure exactly what to make of that fact, and if it's
not important for your other changes then I agree that we should drop
it.

However, it might be good to comment somewhere that your changes (which
are based on values in specific tuples) cannot rely on
ExecGetAllUpdatedCols(), to avoid confusion in the future.

Regards,
    Jeff Davis