Horton

Re: Yet another fast GiST build

Alexander Korotkov <a.korotkov@postgrespro.ru>

View thread View on postgr.es
From: Alexander Korotkov <a.korotkov@postgrespro.ru>
To: Peter Geoghegan <pg@bowt.ie>
Cc: Andrey Borodin <x4mmm@yandex-team.ru>, Darafei Komяpa Praliaskouski <me@komzpa.net>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2019-09-01T17:20:51Z
Lists: pgsql-hackers 
On Fri, Aug 30, 2019 at 6:28 AM Peter Geoghegan <pg@bowt.ie> wrote:
> 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.

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

Commits

  1. Add sortsupport for gist_btree opclasses, for faster index builds.

  2. pageinspect: Fix relcache leak in gist_page_items().

  3. Fix test failure with wal_level=minimal.

  4. Enhance nbtree index tuple deletion.

  5. Fix portability issues in the new gist pageinspect test.

  6. Add functions to 'pageinspect' to inspect GiST indexes.

  7. Fix missing validation for the new GiST sortsupport functions.

  8. Fix compilation warning in xlog.c

  9. Set right-links during sorted GiST index build.

  10. Fix checksum calculation in the new sorting GiST build.

  11. Add support for building GiST index by sorting.