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
like unnest() it would fully decompose the array do individual
elements. what you have above slices the array which is useful,but
probably shouldn't live under the 'unnest' name -- perhaps 'slice'.
Pavel added it to pl/pgsql under the FOREACH syntax (FYI).
merlin