Re: Should AT TIME ZONE be volatile?

On Thu, 2021-11-11 at 09:52 -0500, Tom Lane wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> > I'm not really convinced that ICU is better, either. I think it's more
> > that it isn't used as much.
>
> Well, at least ICU has a notion of attaching versions to collations.
> How mindful they are of bumping the version number when necessary
> remains to be seen.  But the POSIX locale APIs don't even offer the
> opportunity to get it right.

Also, it is much easier *not* to upgrade libicu than it is to *not*
upgrade libc, which an essential component of the operating system.

> > I don't have any constructive proposal for what to do about any of
> > this. It sure is frustrating, though.
>
> Yup.  If we had reliable ways to detect changes in this sort of
> environment-supplied data, maybe we could do something about it
> (a la the work that's been happening on attaching collation versions
> to indexes).  But personally I can't summon the motivation to work
> on that, when ICU is the *only* such infrastructure that offers
> readily program-readable versioning.

Nobody will want to hear that, but the only really good solution would
be for PostgreSQL to have its own built-in collations.

Yours,
Laurenz Albe