nolan(at)celery(dot)tssi(dot)com writes:
> It appears to be necessary to set the array to some non-null value
> before it is possible to update any element in it.
Correct. If you'd like to propose and implement a different behavior,
let's hear it.
I'm not necessarily averse to the idea, but we need a well-thought-out
definition as to why a null array should combine with a non-null
inserted element to yield a non-null result. Most operations in SQL
generate a null if either input is null.
regards, tom lane