Re: NULL in arrays

Tom Lane wrote:
> As we used to say at HP, this is not a bug, it's a definition
> disagreement.  You need to give a coherent argument why we should
> change, not just claim it's wrong.

Additionally, this behavior was discussed during the 7.4 development and
beta cycles on at least a couple occassions -- that would have been the
time to complain, not now. For example, see this thread during beta:
http://archives.postgresql.org/pgsql-hackers/2003-07/msg00747.php

> Given the present lack of support for null elements in arrays, it's
> impossible to have any really pleasant behavior in cases like this.
> But I don't see an inherent reason why "raise an error" is better than
> "return a null array".

In fact, the above referenced thread shows a scenario where the former
behavior is unpleasant.

> I think Joe Conway is planning to tackle that underlying misfeature
> for 7.5.  Whenever it happens, it will result in a number of behavioral
> changes for arrays.  I'm not eager to move the definition around in the
> meantime, especially not in dot-releases.

Agreed. This and a few other changes to bring us closer to SQL99/SQL2003
compliance (see this thread:
   http://archives.postgresql.org/pgsql-hackers/2003-06/msg01167.php
) will cause some reasonably significant behavioral changes.


Joe