Horton

Re: Yet another fast GiST build

Darafei Komяpa Praliaskouski <me@komzpa.net>

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From: Darafei "Komяpa" Praliaskouski <me@komzpa.net>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: "Andrey M. Borodin" <x4mmm@yandex-team.ru>, Pavel Borisov <pashkin.elfe@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, Michael Paquier <michael@paquier.xyz>, Alexander Korotkov <a.korotkov@postgrespro.ru>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-09-09T12:20:43Z
Lists: pgsql-hackers 
On Wed, Sep 9, 2020 at 3:09 PM Heikki Linnakangas <hlinnaka@iki.fi> wrote:

> On 09/09/2020 13:28, Andrey M. Borodin wrote:
> > Thanks Darafei!
> >
> >> 9 сент. 2020 г., в 12:05, Darafei Komяpa Praliaskouski
> >> <me@komzpa.net> написал(а):
> >>
> >>> How does the 'sortsupport' routine interact with
> >>> 'compress'/'decompress'? Which representation is passed to the
> >>> comparator routine: the original value from the table, the
> >>> compressed representation, or the decompressed representation? Do
> >>> the comparetup_index_btree() and readtup_index() routines agree
> >>> with that?
> >>
> ....
>
> Come to think of it, the point z-order comparator could benefit a lot
> from key abbreviation, too. You could do the point -> zorder conversion
> in the abbreviation routine.
>

That's how it works in PostGIS, only that we moved to more
effecient Hilbert curve:
https://github.com/postgis/postgis/blob/54399b9f6b0f02e8db9444f9f042b8d4ca6d4fa4/postgis/lwgeom_btree.c#L171

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.