Re: ICU collation support is incomplete for replacing citext in 10.beta4

Rusty Conover <Rusty(dot)Conover(at)twosigma(dot)com> writes:
> The support for ICU provided collations in PostgreSQL 10.beta4 adds the ability to have case insensitive collations. Which is a great thing, because citext can be very slow!

Apparently you've not read the previous discussions about this.

> Before continuing efforts into resolving these collation challenges, I'd
> like to know if this is considered a bug, or simply out of scope of
> PostgreSQL 10?

It is not a bug, and it is very far out of scope for PG 10.

There's some interest in making this more flexible, but changing the
behavior of hashtext() at all is going to be a pretty hard sell (since
that will break existing hash indexes, which we just got done making into
a production-grade feature). Making it dependent on a selectable ICU
locale seems even more of a nonstarter. And even if we had that working,
as you note, there are other issues that'd need to be resolved. I see
this as something that might possibly get done several years down the
pike.

regards, tom lane