Re: Fix replica identity checks for MERGE command on published table.

On Tue, 8 Jul 2025 at 09:51, Dean Rasheed <dean.a.rasheed@gmail.com> wrote:
>
> Answering my own question, INSERT ... ON CONFLICT DO UPDATE does have
> the same problem as MERGE. To reproduce the error, all you need to do
> is create the unique index it needs *after* creating the publication

The other question is whether we want to back-patch these fixes.

In HEAD, it would be OK to change the signature of
CheckValidResultRel() and pass it an onConflictAction argument to fix
the ON CONFLICT DO UPDATE issue. However, I don't think that such a
change would be back-patchable.

Arguably though, the ON CONFLICT DO UPDATE issue is much less likely
to be a problem in practice, since it looks like it only happens if
the table definition is changed after creating the publication. So
perhaps it would be acceptable to apply and back-patch the original
patch for MERGE to v15, and fix the ON CONFLICT DO UPDATE issue in
HEAD only.

Regards,
Dean