Re: Pg_upgrade and collation

On Tue, Jun 28, 2016 at 02:58:58PM -0700, Peter Geoghegan wrote:
> On Fri, Jun 17, 2016 at 2:51 PM, Alvaro Herrera
> <alvherre(at)2ndquadrant(dot)com> wrote:
> > I think this is way too thin to be helpful:
> >
> >> --- 61,68 ----
> >> checking for compatible compile-time settings, including 32/64-bit
> >> binaries. It is important that
> >> any external modules are also binary compatible, though this cannot
> >> ! be checked by <application>pg_upgrade</>. Compatible collation
> >> ! library versions must also be used.
> >> </para>
>
> Unfortunately, the reality is that as things stand, there is no way to
> test compatibility on all platforms. Glibc does have a notion of
> collation versioning, though [1].

Yes, the patch text is clearly weasel-words in that we can't explain how
to detect incompatible.

> I have long advocated adopting ICU as our defacto standard "collation
> provider", primarily so that we can directly control collations and
> collation versioning. I think that doing this would solve many
> problems. Besides, even SQLite has optional ICU support. PostgreSQL is
> the only major database system that I'm aware of that relies on
> operating system collations exclusively.

I am hopeful ICU has improved enough since we last researched that
support for it will soon be added.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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