Message-ID: <fac50d53f94d846d043cae7ae0361de2a567d30c.camel@cybertec.at>
Subject: Re: ICU Collations and Collation Updates
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Paul Foerster <paul.foerster@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Thomas Michael Engelke <thomas.engelke@posteo.de>, 
	pgsql-general@lists.postgresql.org
Date: Mon, 14 Apr 2025 19:36:36 +0200
In-Reply-To: <23A7395F-6134-4D9E-8489-8F3BCE49E156@gmail.com>
References: <8ed41c50ba6c5322296b869e497c1b5573853b54.camel@posteo.de>
	 <d477c1faf35bad99fe550c8c4c1954ffa076ccfd.camel@cybertec.at>
	 <1257278.1744641400@sss.pgh.pa.us>
	 <23A7395F-6134-4D9E-8489-8F3BCE49E156@gmail.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) 
MIME-Version: 1.0
Archived-At: <https://www.postgresql.org/message-id/fac50d53f94d846d043cae7ae0361de2a567d30c.camel%40cybertec.at>
Precedence: bulk

On Mon, 2025-04-14 at 19:24 +0200, Paul Foerster wrote:
> Hi Tom, hi Laurenz
> > On 14 Apr 2025, at 16:36, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >=20
> > Laurenz Albe <laurenz.albe@cybertec.at> writes:
> > > You would have to build PostgreSQL yourself with a fixed version of I=
CU
> > > that you never upgrade if you want to avoid the problem.
> [...]
> > 2. It's at least *possible* to use your own fixed-version ICU
> > library if you're desperate enough.  I don't think that would work
> > too well for libc; you're stuck with what the platform provides.
>=20
> That topic is interesting because I have a huge problem finding a downtim=
e
> window for our applications to rebuild after the SLES upgrades. I am in t=
he
> process of slowly changing everything to ICU. But limiting downtime is
> essential for me.
>=20
> We always build the PostgreSQL software from source, so if there's a way
> to bake the libicu directly into the software to never change it again
> (beside from recompiling of course), even when building new PostgreSQL
> versions, I'd very much appreciate if if you could let me know how I woul=
d
> do that.
>=20
> The necessity for reindex is a huge problem for us.

You cannot "bake in into" PostgreSQL, but you can grab the ICU source,
install it in /usr/local or similar and build PostgreSQL against that.
You will have to fiddle with CFLAGS and LDFLAGS so that the build process
uses the C headers and libraries from your build of the ICU library.

Yours,
Laurenz Albe