Re: insensitive collations

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