On Wed, 2023-10-11 at 08:51 +0200, Peter Eisentraut wrote: > I don't see how this would really work in practice. Whether your > data > has unassigned code points or not, when the collations are updated to > the next Unicode version, the collations will have a new version > number, > and so you need to run the refresh procedure in any case.
Even with a version number, we don't provide a great reresh procedure or document how it should be done. In practice, avoiding unassigned code points might mitigate some kinds of problems, especially for glibc which has a very coarse version number. In any case, a CHECK constraint to avoid unassigned code points has utility to be forward-compatible with normalization, and also might just be a good sanity check. Regards, Jeff Davis