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