Re: [PATCH] Exorcise "zero-dimensional" arrays (Was: Re: Should array_length() Return NULL)

Josh Berkus <josh@agliodbs.com> writes:
> On 06/12/2013 11:01 AM, Tom Lane wrote:
>> I'm going to be disappointed if all we can get out of this is
>> a cardinality() function, and nothing is done about the empty-array
>> semantics.

> Well, we can't change the zero-dim behavior without breaking backwards
> compatibility.  And enough people piled on to say NO to that, that it
> went by the wayside.

Meh.  Robert was pretty vocal about it, but it wasn't clear to me that
his was the majority opinion, and in any case there wasn't much
consideration given to compromises falling somewhere between "no
changes" and the rather drastic solution Brendan proposed.  For
instance, it's really hard to believe that this is a good thing:

regression=# select array_dims('{}'::int[]) is null;?column? 
----------t
(1 row)

Whatever you think the dimensions of that are, surely they're not
unknown.
        regards, tom lane