Re: obsoleting plpython2u and defaulting plpythonu to plpython3u

Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> writes:
> On 4/25/18 04:50, Pavel Raiskup wrote:
>> So full drop is not what ask for now (it will be needed for lts/enterprise
>> distros for quite some time anyway), I just think that plpython3 should be
>> the default (by build system, by 'plpythonu'=>'plpython3u', etc.).

> I don't think we should do that unless there is an update to PEP 394.

PEP 394 points out that some distros (at least Arch) have already switched
"python" to mean "python3", and I gather from Pavel's inquiry that the day
is in sight when Fedora will do that. Perhaps we should think about
providing a configure switch to control whether "plpythonu" means
"plpython2u" or "plpython3u", so that distros can reasonably easily sync
PG's behavior with whatever they've chosen to do with the python shell
command. I agree that it's not PG's business to be out in front of this
change, but maybe we shouldn't be holding it back, either.

I'm not very sure how many moving parts would be involved in making that
happen. One thing we should probably do first is retire the pg_pltemplate
system catalog in favor of making PL extension scripts self-contained,
as you'd mentioned recently would be a good project to finish off.

regards, tom lane