Re: min/max aggregation for jsonb

On 03.03.23 11:41, David Rowley wrote:
> On Fri, 3 Mar 2023 at 23:17, Daneel Yaitskov <dyaitskov(at)gmail(dot)com> wrote:
>> I wanted to use min/max aggregation functions for jsonb type and noticed
>> there is no functions for this type, meanwhile string/array types are supported.
>
> It's not really clear to me how you'd want these to sort. If you just
> want to sort by what the output that you see from the type's output
> function then you might get what you need by casting to text.
>
>> Is there a concern about implementing support for jsonb in min/max?
>
> I imagine a lack of any meaningful way of comparing two jsonb values
> to find out which is greater than the other is of some concern.

We already have ordering operators and operator classes for jsonb, so
sticking min/max aggregates around that should be pretty straightforward.