Jeff Davis wrote:
> On Sun, 2008-01-27 at 22:11 -0800, Neil Conway wrote:
>> p. 564 discusses the required behavior. The result of array_agg() is an
>> array with one element per input value, sorted according to the optional
>> ORDER BY clause. NULL input values are included in the array, and the
>> result for an empty group is NULL, not an empty array. Note that per
>> page 66, I'd expect array values in the input to array_agg() not to be
>> flattened.
>
> Should there be an inverse operator (a SRF, in this case) that returns a
> set from an array?
Yes -- see UNNEST
Joe