Re: Supporting MERGE on updatable views

On Sat, 21 Jan 2023 at 11:03, Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com> wrote:
>
> Rebased version, following 5d29d525ff.
>

Updated version attached.

This needed a little extra tweaking to work following the change to
make Vars outer-join aware, so it's worth checking that I understood
that properly -- when merging into a trigger-updatable view, the
whole-row Var added to the targetlist by the rewriter is nullable by
the join added by transform_MERGE_to_join().

The make-Vars-outer-join-aware patch has possibly made this patch's
change to preprocess_targetlist() unnecessary, but I left it in just
in case, even though I can no longer trigger that failure mode. It
feels safer, and more consistent with the code later on in that
function.

Regards,
Dean