Re: BUG #15285: Query used index over field with ICU collation in some cases wrongly return 0 rows

On Thu, Jul 19, 2018 at 9:44 AM, Peter Geoghegan <pg@bowt.ie> wrote:
> It appears that the main support function 1 routine disagrees with the
> CREATE INDEX sort order, which is wrong. I'll try to isolate the
> problem a bit further.

As far as I can tell, this is an ICU bug. ucol_strcollUTF8() is buggy
with this digitslast collation, which ucol_nextSortKeyPart() fails to
be bug-compatible with. Other similar customized collations (e.g.
'en-u-kf-upper') work fine. (Ugh, that's familiar in an unpleasant
way.)

I'm using libicu60. What version are you using, Roman?

I tried to find something that matches this on the ICU bug tracker.
This might be a match: https://ssl.icu-project.org/trac/ticket/12518

-- 
Peter Geoghegan