On Mon, Sep 25, 2017 at 09:36:44AM -0700, Peter Geoghegan wrote: > On Mon, Sep 25, 2017 at 9:06 AM, Robert Haas <robertmh...@gmail.com> wrote: > >> The big concern I have here is that this feels a lot like something that > >> we'll regret at leisure, if it's not right in the first release. I'd > >> much rather be restrictive in v10 and then loosen the rules later, than > >> be lax in v10 and then have to argue about whether to break backwards > >> compatibility in order to gain saner behavior. > > > > I think it's inevitable that a certain number of users are going to > > have to cope with ICU version changes breaking stuff. > > Wasn't the main point of adopting ICU that that doesn't happen when it > isn't essential? There will be some risk with pg_dump across ICU > versions, due rare to political changes. But, on pg_upgrade, the old > collations will continue to work, even if they would not have appeared > at initdb time on that ICU version, because ICU has all kinds of > fallbacks.
I wouldn't describe it that way. I agree that few, if any, ICU upgrades will remove country or language codes. Overall, though, almost every ICU upgrade will be difficult. Each ICU release, even a minor release like 58.2, changes the sorting rules in some tiny way. You then see "Rebuild all objects affected by this collation" messages. -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers