Re: Add new protocol message to change GUCs for usage with future protocol-only GUCs

On Thu, May 23, 2024 at 11:12 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> If a reader doesn't recognize a particular
> chunk code, it can still tell whether the chunk is "critical" or not,
> and thereby decide if it must give up or can proceed while ignoring
> that chunk.)

Would it be good to expand on that idea of criticality? IIRC one of
Jelte's complaints earlier was that middleware has to know all the
extension types anyway, to be able to figure out whether it has to do
something about them or not. HTTP has the concept of hop-by-hop vs
end-to-end headers for related reasons.

--Jacob