Horton

Re: pgsql: libpq: Grease the protocol by default

Jacob Champion <jacob.champion@enterprisedb.com>

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From: Jacob Champion <jacob.champion@enterprisedb.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Jelte Fennema-Nio <postgres@jeltef.nl>, pgsql-hackers@lists.postgresql.org, Andrew Dunstan <andrew@dunslane.net>
Date: 2026-02-23T22:51:46Z
Lists: pgsql-hackers 
On Mon, Feb 23, 2026 at 2:18 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Either that or we decide that it's time to throw 9.2 support
> overboard (looks like 9.3 and up are fine).

Well, while I was hacking on a patch I realized that 9.3 (all the way
up to 10) is only okay if you're running a sufficiently patched
version. PG11 is the first to support negotiation for the whole
release line.

> If it's not hard to add the connection option to this test, let's do
> that --- but if it is a problem, I wouldn't shed too many tears over
> moving the oldest-old-version goalpost.  I think we might not be able
> to fix the test without changing buildfarm client script and/or
> configuration.

I think Jelte said it well back on the -committers thread:

> Why only force max_protocol_version=3.0 for beta? It sounds like
> this would also be an issue once we eventually bump the default
> version.

So a fix belongs in pg_upgrade, IMO, instead of the test. I have a
draft passing locally that I should be able to share soon.

Thanks,
--Jacob

Commits

  1. pg_upgrade: Use max_protocol_version=3.0 for older servers

  2. libpq: Grease the protocol by default

  3. libpq: Prepare for protocol grease during 19beta