From: | Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> |
---|---|
To: | Peter Geoghegan <pg(at)bowt(dot)ie> |
Cc: | Andrey Borodin <x4mmm(at)yandex-team(dot)ru>, Darafei Komяpa Praliaskouski <me(at)komzpa(dot)net>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Yet another fast GiST build |
Date: | 2019-09-01 17:20:51 |
Message-ID: | CAPpHfdtLY+JHK6RrFuvprnAXFk=ybF0n=FzL2rqPybFZajxD2A@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Fri, Aug 30, 2019 at 6:28 AM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> On Thu, Aug 29, 2019 at 8:22 PM Alexander Korotkov
> <a(dot)korotkov(at)postgrespro(dot)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.
Sure, our prototype was an implementation of one of such papers. My
point is that advantages of Z-value ordered GiST for spatial joins are
not yet clear for me. Except faster build and smaller index, which
are general advantages.
------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
From | Date | Subject | |
---|---|---|---|
Next Message | David Fetter | 2019-09-01 18:00:26 | Proposal: roll pg_stat_statements into core |
Previous Message | Alexander Korotkov | 2019-09-01 17:17:48 | Re: Yet another fast GiST build |