Hi,

I tried to implement it using ObjectHolder and ComplexWriter and it doesn't
seem possible to achieve something general at this point.

Andrea

On Wed, Nov 21, 2018 at 6:02 PM Andrea Sella <[email protected]> wrote:

> Hi,
>
> I've just started with Apache Drill and I'd like to write a custom
> aggregate function in order to concatenate array fields.
>
> I have seen that the feature is still in alpha and before trying to make
> it work I would like to know if at this stage my custom function is
> possible.
>
> The main idea is trying to achieve something like this:
> a,b
> foo, [1,2,3]
> foo, [3,5,6]
>
> > select my_custom_fun(b) from table group by a
> > foo, [1,2,3,3,5,6]
>
> If it is possible, there are any other available documentation other than
> this section[1]?
>
> Thank you,
> Andrea
>
> [1] https://drill.apache.org/docs/developing-an-aggregate-function/
>


-- 
BR,
Andrea

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