Re: WIP: Upper planner pathification

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Mon, Mar 14, 2016 at 9:21 PM, Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com> wrote:
>> So, even though we don't need to define multiple hook declarations,
>> I think the hook invocation is needed just after create_xxxx_paths()
>> for each. It will need to inform extension the context of hook
>> invocation, the argument list will take UpperRelationKind.

> That actually seems like a pretty good point. Otherwise you can't
> push anything from the upper rels down unless you are prepared to
> handle all of it.

I'm not exactly convinced of the use-case for that. What external
thing is likely to handle window functions but not aggregation,
for example?

regards, tom lane