Horton

Re: Built-in CTYPE provider

Jeff Davis <pgsql@j-davis.com>

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From: Jeff Davis <pgsql@j-davis.com>
To: Noah Misch <noah@leadboat.com>
Cc: Peter Eisentraut <peter@eisentraut.org>, Daniel Verite <daniel@manitou-mail.org>, Robert Haas <robertmhaas@gmail.com>, Jeremy Schneider <schneider@ardentperf.com>, pgsql-hackers@postgresql.org
Date: 2024-07-05T21:38:45Z
Lists: pgsql-hackers 
On Thu, 2024-07-04 at 14:26 -0700, Noah Misch wrote:
> I think you're saying that if some Unicode update changes the results
> of a
> STABLE function but does not change the result of any IMMUTABLE
> function, we
> may as well import that update.  Is that about right?  If so, I
> agree.

If you are proposing that Unicode updates should not be performed if
they affect the results of any IMMUTABLE function, then that's a new
policy.

For instance, the results of NORMALIZE() changed from PG15 to PG16 due
to commit 1091b48cd7:

  SELECT NORMALIZE(U&'\+01E030',nfkc)::bytea;

  Version 15: \xf09e80b0

  Version 16: \xd0b0

I am neither endorsing nor opposing the new policy you propose at this
time, but deep in the sub-thread of one particular feature is not the
right place to discuss it.

Please start a new thread for the proposed PG18 policy change and CC
me. I happen to think that around the release of the next version of
Unicode (in a couple months) would be the most productive time to have
that discussion, but you can start the discussion now if you like.

Regards,
	Jeff Davis

Commits

  1. Support PG_UNICODE_FAST locale in the builtin collation provider.

  2. Support Unicode full case mapping and conversion.

  3. Fix test failures when language environment is not UTF-8.

  4. Add unicode_strtitle() for Unicode Default Case Conversion.

  5. Use version for builtin collations.

  6. Fix convert_case(), introduced in 5c40364dd6.

  7. Inline basic UTF-8 functions.

  8. Support C.UTF-8 locale in the new builtin collation provider.

  9. Fix another warning, introduced by 846311051e.

  10. Address more review comments on commit 2d819a08a1.

  11. Fix unreachable code warning from commit 2d819a08a1.

  12. Introduce "builtin" collation provider.

  13. Catalog changes preparing for builtin collation provider.

  14. Unicode case mapping tables and functions.

  15. Add Unicode property tables.

  16. Documentation update for Standard Collations.

  17. Cleanup for unicode-update build target and test.

  18. Shrink Unicode category table.

  19. Make some error strings more generic

  20. pg_upgrade: copy locale and encoding information to new cluster.

  21. Update Unicode data to Unicode 15.0.0

  22. Create a new type category for "internal use" types.