Re: Single-argument variant for array_length and friends?

2013/3/21 Brendan Jurd <direvus@gmail.com>:
> On 21 March 2013 17:32, Pavel Stehule <pavel.stehule@gmail.com> wrote:
>> If I though about it more, I like to more limit one parametric
>> array_length function just for only 1D array. So it is your A use
>> case. But I understand so this variant is not orthogonal. Hard to say,
>> what is better.
>>
>
> Yes, for me (a) is running a very close 2nd place to (c).  The
> strength of (a) is it means we aren't making guesses about the user's
> intention.  When a user concocts an expression that is ambiguous, I
> feel it is usually good to kick it back to them and ask them to be
> more precise.
>
> On the other hand, I find it very natural to interpret "what is the
> length of my multidim array" to mean "what is the length of the
> outermost dimension of my multidim array", because to me a multidim
> array is just an array that contains more arrays.

lot of postgresql functions calculate with all items in array without
respect to dimensions - like unnest.

so concept "use outermost dim" is not in pg now, and should not be
introduced if it is possible. More it goes against a verbosity concept
introduced by ADA and reused in PL/SQL and PL/pgSQL.

regards

Pavel

>
> Cheers,
> BJ