On Jan10, 2014, at 11:00 , Merlin Moncure <mmoncure@gmail.com> wrote:
> On Fri, Jan 10, 2014 at 3:52 AM, Marko Tiikkaja <marko@joh.to> wrote:
>> On 1/10/14, 10:41 AM, Merlin Moncure wrote:
>>>
>>> What's needed for better iteration support (IMO)
>>> is a function that does what unnest does but returns an array on
>>> indexes (one per dimsension) -- a generalization of the
>>> _pg_expandarray function. Lets' say 'unnest_dims'.
>>
>>
>> So unnest_dims('{{1,2},{3,4}}'::int[]) would return VALUES (1,
>> '{1,2}'::int[]), (2, '{3,4}'::int[])? If so, then yes, that's a
>> functionality I've considered us to have been missing for a long time.
>
> not quite. it returns int[], anyelement: so, using your example, you'd get:
>
> [1,1], 1
> [1,2], 2
> [2,1], 3
> [2,2], 4
Now that we have WITH ORDINALITY, it'd be sufficient to have a
variant of array_dims() that returns int[][] instead of text, say
array_dimsarray(). Your unnest_dims could then be written as
unnest(array_dimsarray(array)) with ordinality
best regards,
florian pflug