On Mon, Dec 8, 2025 at 1:43 PM Jelte Fennema-Nio <postgres@jeltef.nl> wrote:
> 1. We still have fairly limited experience with protocol options, so
> afaik not everyone agrees what we should use a version bump for vs a
> protocol extension.
I think it'd be helpful for proposals to describe why a minor version
bump was chosen over a protocol extension parameter (or vice versa),
so that we can begin to develop some consensus.
To me, the conversation on the wire for this feature seems perfect for
an extension parameter: "Hello server, do you support this optional
thing in this one message type? If not, let me know." Especially since
the optional thing is itself an extensible bitmap! With the
minor-version strategy, if we added new bits in 3.6, clients who just
wanted those new bits would then have to implement support for every
feature in versions 3.4, 3.5, and 3.6 just to improve that one use
case, and that incentive mismatch leads to more ossification IMO.
= Soapbox Follows =
I've talked about it face-to-face with people, but to go on the public
record: I don't think this is a wise use of a minor version upgrade
strategy. I prefer protocol architectures that introduce separate
extensions first, then periodically bundle the critical and
highly-used extensions into a new minor version once they're sure that
_everyone_ should support those things.
I know that 3.2 didn't do that. My view of 3.2 is that it was a big
compromise to get some things unstuck, so overall I'm glad we have it
-- but now that we have it, I'd rather that 3.next be more
intentional. Plus I think it's unwise to introduce a 3.3 before we're
confident that 3.2 can be widely deployed, and I'm trying to put
effort into the latter for 19, so that I'm not just sitting here
gatekeeping.
IETF has a bunch of related case studies [1,2,3] that might be useful
reading, even if we decide that their experience differs heavily from
ours.
--Jacob
[1] https://www.rfc-editor.org/rfc/rfc5218
[2] https://www.rfc-editor.org/rfc/rfc8170
[3] https://www.rfc-editor.org/rfc/rfc9170
