Tom Lane wrote:
>It's something that's on the ever-growing TODO list ... I dunno if
>anyone has any near-term plans to work on it. It'd definitely be
>nice to teach the planner to do joins-over-unions well, and then
>make inheritance just invoke that behavior instead of being a crocky
>special case.
>
>
Sounds good; currently if you use the polymorphism of inherited tables,
and happen to cross 2 such tables, you get O(n^2) performance.