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

On Fri, Jul 20, 2018 at 11:26 AM, Peter Geoghegan <pg@bowt.ie> wrote:
> 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

FWIW I see the same result with icu 61.1 and 62.1_1 from FreeBSD ports.

-- 
Thomas Munro
http://www.enterprisedb.com