On Thu, Aug 29, 2019 at 8:22 PM Alexander Korotkov
<a.korotkov@postgrespro.ru> wrote:
> Alternatively you can encode size in Z-value. But this increases
> dimensionality of space and decreases efficiency of join. Also,
> spatial join can be made using two indexes, even just current GiST
> without Z-values. We've prototyped that, see [1].
I'm pretty sure that spatial joins generally need two spatial indexes
(usually R-Trees). There seems to have been quite a lot of research in
it in the 1990s.
--
Peter Geoghegan