Understood, and backwards compatibility also of course. Thank you On Fri, Dec 2, 2016 at 7:20 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
> otar shavadze <oshava...@gmail.com> writes: > > SELECT ARRAY_LENGTH('{}'::INT[], 1) > > This returns NULL, not so "dangerous" either way, not would be more > > logically, if array length function will return 0 from empty array, > > instead of NULL ? > > Well, the issue is that you're asking about dimension 1 of a > zero-dimensional array, so the answer is indeed undefined, not 0. > > A lot of people are not terribly happy with PG's array handling, > but there's enough interconnectedness to the behaviors that it's > hard to change just one thing ... and there's also backwards > compatibility to worry about. > > regards, tom lane >