Re: pgsql: libpq: Grease the protocol by default

On Tue, Feb 24, 2026 at 9:18 AM Jacob Champion
<jacob(dot)champion(at)enterprisedb(dot)com> wrote:
> I still need to run a sanity check with the
> other 9.x lines to make sure I've selected the right cutoffs.

The cutoffs don't behave the way I thought they would.

Yesterday, I was about to complain that cluster.major_version was
poorly named -- why call it that if you have to pass it through
GET_MAJOR_VERSION() to get at what you want? -- but it does in fact
contain _only_ the major version information, because that's all that
PG_VERSION tells us. And unfortunately we don't save the result of the
version check for the old postgres binary anywhere.

So pg_upgrade will use max_protocol_version=3.0 with all servers v10
and below, in practice. There's nothing wrong with that behavior, but
I think I should switch to a simple `< 1100` check in the code to
avoid misleading people, unless anyone has a better way that won't
significantly increase the cost of the backport. (I could potentially
follow up with an improvement on HEAD, if the cost-benefit makes
sense, but I'm not sure it does.)

--Jacob