Re: pg_partition_tree crashes for a non-defined relation

On Sun, Dec 09, 2018 at 02:07:29PM -0500, Tom Lane wrote:
> Stephen Frost <sfrost(at)snowman(dot)net> writes:
>> I don't entirely buy off on the argument that it's code that's 'highly
>> unlikely to break once written' though- we do add new relkinds from time
>> to time, for example. Perhaps we could have these functions run just
>> once per relkind.
>
> Well, the relevant code is likely to be "if relkind is not x, y, or z,
> then PG_RETURN_NULL". If we add a new relkind and forget to consider the
> function, the outcome is a NULL result that perhaps should not have been
> NULL ... but a test like this won't help us notice that.

Yes, in order to prevent problems with newly-introduced relkinds, I
think that the checks within functions should be careful to check only
for relkinds that they support, and not list those they do not support.
--
Michael