From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: Peter Geoghegan <pg@bowt.ie>, Thomas Munro <thomas.munro@gmail.com>,
        Jeremy Schneider <schneider@ardentperf.com>,
        Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
        pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: Collation version tracking for macOS
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Wed, 08 Jun 2022 07:46:04 -0400"
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Date: Wed, 08 Jun 2022 13:42:21 -0400
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Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Jun 7, 2022 at 4:10 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I mean by "false positive" is telling every macOS user that they'd better
>> reindex everything every year, when in point of fact Apple changes those
>> collations almost never.

> Do we actually know that to be true? Given how fast things seem to be
> getting added to Unicode, it wouldn't surprise me at all if they're
> updating their Unicode tables for new characters with some regularity,
> if nothing else, and that's a breaking change for us.

Their POSIX collations seem to be legacy code that's entirely unrelated to
any modern collation support; in particular the "UTF8" ones are that in
name only.  I'm sure that Apple are indeed updating the UTF8 data behind
their proprietary i18n APIs, but the libc APIs are mostly getting benign
neglect.

Maybe the report that started this thread indicates that this is changing,
but I'll believe that when I see it.

			regards, tom lane