On Wed, Jun 8, 2022 at 10:39 PM Peter Geoghegan <p...@bowt.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__vgr9arqqohmqwg...@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