On Mon, Feb 20, 2017 at 3:51 PM, Bruce Momjian <bruce@momjian.us> wrote:
> So we don't have any other cases where we warn about possible corruption
> except this?
I'm not sure that I understand the distinction you're making.
> Also, I will go back to my previous concern, that while I like the fact
> we can detect collation changes with ICU, we don't know if ICU
> collations change more often than OS collations.
We do know that ICU collations can never change behaviorally in a
given stable release. Bug fixes are allowed in point releases, but
these never change the user-visible behavior of collations. That's
very clear, because an upstream Unciode UCA version is used by a given
major release of ICU. This upstream data describes the behavior of a
collation using a high-level declarative language, that non-programmer
experts in natural languages write.
ICU versions many different things, in fact. Importantly, it
explicitly decouples behavioral issues (user visible sort order -- UCA
version) from technical issues (collator implementation details). So,
my original point is that that could change, and if that happens we
ought to have a plan. But, it won't change unless it really has to.
--
Peter Geoghegan