On 04/01/2019 17:05, Daniel Verite wrote:
> When using GROUP BY and ORDER BY on a field with a non-deterministic
> collation, this pops out:
>
> CREATE COLLATION myfr (locale='fr-u-ks-level1',
> provider='icu', deterministic=false);
>
> =# select n from (values ('été' collate "myfr"), ('ete')) x(n)
> group by 1 order by 1 ;
> n
> -----
> ete
> (1 row)
>
> =# select n from (values ('été' collate "myfr"), ('ete')) x(n)
> group by 1 order by 1 desc;
> n
> -----
> été
> (1 row)
I don't see anything wrong here. The collation says that both values
are equal, so which one is returned is implementation-dependent.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
