Re: Collation version tracking for macOS

On Wed, Jun 8, 2022 at 10:39 PM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> They simply REINDEX, without changing anything. The details are still
> fuzzy, but at least that's what I was thinking of.

As I said before, BCP47 format tags are incredibly forgiving by
design. So it should be reasonable to assume that anything that has
worked in an earlier version of ICU will continue to work in a way
that's at least as useful in a future version. See:

https://www.postgresql.org/message-id/CAH2-Wz=ZrA5Yf55pKtdJb2pYCVN=2dh__VGR9arQqOHMqWgQPg@mail.gmail.com

That's not strictly guaranteed, because sometimes countries cease to
exist, and their ISO country codes eventually go away too. But that
still tends to fail gracefully. It's mostly only relevant for things
that are part of a locale, which is a broader concept than just
collation. An application that did this and relied on ICU for
localization might then find that the currency sign changed, but I'm
not aware of any impact on locales. You can ask for total nonsense
and mostly get reasonable behaviors, like Japanese as spoken in
Iceland. Even some totally made up (or misspelled) country is
accepted without complaint.

--
Peter Geoghegan