On Fri, Nov 13, 2009 at 7:54 AM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
> Andrew Gierth wrote:
>> Herewith a patch to implement agg(foo ORDER BY bar) with or without
>> DISTINCT, etc.
>
> What does that mean? Aggregate functions are supposed to be commutative,
> right?
We certainly have non-commutative agggregates currently, notably array_agg()
I suspect it would be good to have a flag marking the commutative ones
--
greg