Re: Switching PL/Python to Python 3 by default in PostgreSQL 12

The point of the links I sent from the Python community is that they wanted
Python extinct in the wild as of Jan 1 next year. They are never fixing it,
even for a security vulnerability.

It seems to me we roll out breaking changes with major versions. So yes, if
the user chooses to upgrade to 12 and they haven't migrated their code to
Python 2 it might not work.

I don't have a good answer to no changes except regressions. I do hope,
given how much our users expect us to be secure, that we weigh the
consequences of making our default Python a version which is dead to the
community a month or so after Postgresql 12s release. We can certainly take
the stance of leave the Python version be, but it seems that we should then
come up with a plan if there is a security vulnerability found in Python 2
after Jan 1st 2020.

If Python 2 wasn't our *default* choice then I would be much more
comfortable letting this just pass without mention.

All that aside, I think allowing the admin set the default version of
plpythonu to be an excellent idea.

Thanks
Steve

On Sun, Jul 7, 2019, 8:26 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> writes:
> > On 2019-07-07 00:34, Steven Pousty wrote:
> >> Why would it be a 13 or later issue?
>
> > Because PostgreSQL 12 is feature frozen and in beta, and this issue is
> > not a regression.
>
> More to the point: it does not seem to me that we should change what
> "plpythonu" means until Python 2 is effectively extinct in the wild.
> Which is surely some years away yet. If we change it sooner than
> that, the number of people complaining that we broke perfectly good
> installations will vastly outweigh the number of people who are
> happy because we saved them one keystroke per function definition.
>
> As a possibly relevant comparison, I get the impression that most
> packagers of Python are removing the versionless "python" executable
> name and putting *nothing* in its place. You have to write python2
> or python3 nowadays. Individuals might still be setting up symlinks
> so that "python" does what they want, but it's not happening at the
> packaging/distro level.
>
> (This comparison suggests that maybe what we should be thinking
> about is a way to make it easier to change what "plpythonu" means
> at the local-opt-in level.)
>
> regards, tom lane
>