From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jacob Champion <jacob.champion@enterprisedb.com>
cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: PG20 Minimum Dependency Thread
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Comments: In-reply-to Jacob Champion <jacob.champion@enterprisedb.com>
	message dated "Thu, 18 Jun 2026 14:42:50 -0700"
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Date: Thu, 18 Jun 2026 18:26:06 -0400
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Jacob Champion <jacob.champion@enterprisedb.com> writes:
> On Thu, Jun 18, 2026 at 2:22 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> so it kind of doesn't
>> matter today whether we set N to 2 or 3.

> I think it still matters for impending decisions. For example, we're
> about to engineer how to backport a sliding window of Python across
> the sliding window of backbranch support. Shorter windows tie our
> hands less.

I dunno.  One of the points of the allegedly-agreed-to policy
framework was

>>> 2) We don't remove support for OS versions in minor releases

A strict reading of that is that a released branch can't increase
its minimum required Python version.

Now maybe we can finesse that, like "you can build PL/Python and
associated contrib modules with Python >= X, but if you want to
run these optional tests, they require Python >= Y".  Not sure
how comfortable I am with that.  I definitely don't want to get
into a situation where we require buildfarm owners to have
Python >= Y installed, because then we will not have any testing
that proves we didn't break the other part.  (So we'd need a
runtime check to skip these tests on too-old Python.)

In any case, if we do make such a decision, most likely we'd
use the same value of Y for all the active back branches.
So I think the value of N in the support policy really
only matters for future version-cutoff decisions.

			regards, tom lane