Horton

Re: Collation versioning

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Juan José Santamaría Flecha <juanjo.santamaria@gmail.com>, David Rowley <dgrowleyml@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Julien Rouhaud <rjuju123@gmail.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>, Laurenz Albe <laurenz.albe@cybertec.at>, Douglas Doole <dougdoole@gmail.com>, Christoph Berg <myon@debian.org>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2021-04-15T22:45:46Z
Lists: pgsql-hackers

Attachments

On Mon, Mar 15, 2021 at 2:25 PM Thomas Munro <thomas.munro@gmail.com> wrote:
> FYI I have added this as an open item for PostgreSQL 14.  My default
> action will be to document this limitation, if we can't come up with
> something better in time.

Here is a short doc update to explain the situation on Windows and
close that open item.

PS  While trying to find official names to use to refer to the "en-US"
and "English_United States.1252" forms, I came across these sentences
in the Windows documentation[1], which support the idea already
discussed of trying to prevent the latter format from ever entering
our catalogs, in some future release:

"The locale-name form is a short, IETF-standardized string; for
example, en-US for English (United States) or bs-Cyrl-BA for Bosnian
(Cyrillic, Bosnia and Herzegovina).  These forms are preferred. [...]"

"The language[_country-region[.code-page]] form is stored in the
locale setting for a category when a language string, or language
string and country or region string, is used to create the locale.
[...] We do not recommend this form for locale strings embedded in
code or serialized to storage, because these strings are more likely
to be changed by an operating system update than the locale name
form."

[1] https://docs.microsoft.com/en-us/cpp/c-runtime-library/locale-names-languages-and-country-region-strings?view=msvc-160

Commits

  1. Doc: Document known problem with Windows collation versions.

  2. Add collation versions for FreeBSD.

  3. Tolerate version lookup failure for old style Windows locale names.

  4. Track collation versions for indexes.

  5. Add pg_depend.refobjversion.

  6. Remove pg_collation.collversion.

  7. Fix the MSVC build for versions 2015 and later.

  8. Add collation versions for Windows.

  9. Implement type regcollation

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

  11. Make type "name" collation-aware.