Re: ICU for global collation

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: m.polyakova@postgrespro.ru
Cc: pgsql-hackers@postgresql.org, pryzby@telsasoft.com, rjuju123@gmail.com, daniel@manitou-mail.org, AndrewBille@gmail.com, michael@paquier.xyz, peter.eisentraut@enterprisedb.com
Date: 2022-09-15T06:52:10Z
Lists: pgsql-hackers
At Wed, 14 Sep 2022 17:19:34 +0300, Marina Polyakova <m.polyakova@postgrespro.ru> wrote in 
> Hello!
> 
> I was surprised that it is allowed to create clusters/databases where
> the default ICU collations do not actually work due to unsupported
> encodings:
> 
> $ initdb --encoding SQL_ASCII --locale-provider icu --icu-locale en-US
> -D data &&
> pg_ctl -D data -l logfile start &&
> psql -c "SELECT 'a' < 'b'" template1
> ...
> waiting for server to start.... done
> server started
> ERROR:  encoding "SQL_ASCII" not supported by ICU

Indeed. If I did the following, the direction of the patch looks fine
to me.

If I executed initdb as follows, I would be told to specify
--icu-locale option.

> $ initdb --encoding sql-ascii --locale-provider icu hoge
> ...
> initdb: error: ICU locale must be specified

However, when I reran the command, it complains about incompatible
encoding this time.  I think it's more user-friendly to check for the
encoding compatibility before the check for missing --icu-locale
option.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center



Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Add CHECK_FOR_INTERRUPTS while restoring changes during decoding.

  2. Improve ICU option handling in CREATE DATABASE

  3. Don't allow creation of database with ICU locale with unsupported encoding

  4. Make locale option behavior more consistent

  5. pg_dump: Dump colliculocale

  6. Remove further unwanted linker flags from perl_embed_ldflags

  7. Doc: document possible need to raise kernel's somaxconn limit.

  8. Reduce warnings with -Wshadow=compatible-local builds

  9. Remove redundant spaces in _outA_Expr() output

  10. Fix outdated --help message for postgres -f

  11. pg_upgrade: Fix version comparison for global ICU support

  12. Silence -Wmaybe-uninitialized compiler warning in dbcommands.c.

  13. Add option to use ICU as global locale provider

  14. DefineCollation() code cleanup

  15. Change collate and ctype fields to type text

  16. Call pg_newlocale_from_collation() also with default collation

  17. Use libc version as a collation version on glibc systems.

  18. Silence -Wmaybe-uninitialized compiler warnings in dbcommands.c.

  19. Make LC_COLLATE and LC_CTYPE database-level settings. Collation and