On 09/01/2019 22:01, Daniel Verite wrote:
>> I don't see anything wrong here. The collation says that both values
>> are equal, so which one is returned is implementation-dependent.
> Is it, but it's impractical if the product of seemingly the same GROUP BY
> flip-flops between its different valid results. If it can't be avoided, then
> okay. If it can be avoided at little cost, then it would be better to do it.
But there is no concept of which one of these is the preferred variant,
so I don't see how the system is supposed to pick one and then stick to
it across separate query invocations.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
