Re: What users can do with custom ICU collations in Postgres 10

On 10 August 2017 at 06:49, Peter Geoghegan <pg(at)bowt(dot)ie> wrote:

> There are actually very many customizations to collations that are
> possible beyond what the "stock" ICU collations provide (whatever
> "stock" means). Some of these are really cool, and I can imagine use
> cases where they are very compelling that have nothing to do with
> internationalization (such customizations are how we should eventually
> implement case-insensitive collations, once the infrastructure for
> doing that without breaking hashing is in place).
>
> I'd like to give a demo on what is already possible, but not currently
> documented. I didn't see anyone else comment on this, including Peter
> E (maybe I missed that?). We should improve the documentation in this
> area, to get this into the hands of users.
>
> Say we're unhappy that numbers come first, which we see here:
>
>
Ooh, this finally gives us a path toward case-insensitive default database
collation via CLDR caseLevel.

http://userguide.icu-project.org/collation

http://www.unicode.org/reports/tr35/tr35-collation.html#Algorithm_Case

That *definitely* should be documented and exposed by initdb.

--
Craig Ringer http://www.2ndQuadrant.com/
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