Re: Should AT TIME ZONE be volatile?

Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at> writes:
> On Thu, 2021-11-11 at 09:52 -0500, Tom Lane wrote:
>> 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.

And our own tzdb too? Maybe an outfit like Oracle has the resources
and will to maintain their own copies of such data, but I can't see
us wanting to do it.

tzdb has an additional problem, which is that not updating is not an
option: if you're affected by a DST law change, you want that update,
and you frequently need it yesterday. We're definitely not set up
to handle that sort of update process, which is why we recommend
--with-system-tzdata.

regards, tom lane