Horton

Re: Yet another fast GiST build

Pavel Borisov <pashkin.elfe@gmail.com>

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From: Pavel Borisov <pashkin.elfe@gmail.com>
To: Andrey Borodin <x4mmm@yandex-team.ru>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Tom Lane <tgl@sss.pgh.pa.us>, Justin Pryzby <pryzby@telsasoft.com>, Darafei Komяpa Praliaskouski <me@komzpa.net>, Thomas Munro <thomas.munro@gmail.com>, Michael Paquier <michael@paquier.xyz>, Alexander Korotkov <a.korotkov@postgrespro.ru>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-10-21T17:35:27Z
Lists: pgsql-hackers 
>
>
> >> +    return (ia->lower > ib->lower) ? 1 : -1;
> >> +}
> >
> > We're only dealing with leaf items during index build, so the 'upper'
> and 'lower' should always be equal here, right? Maybe add a comment and an
> assertion on that.
> >
> > (It's pretty sad that the on-disk representation is identical for leaf
> and internal items, because that wastes a lot of disk space, but that's way
> out of scope for this patch.)
>
> Thanks, I've added assert() where is was easy to test equalty.
>
> PFA patch with all types.
>
> I had a plan to implement and test one type each day. I did not quite
> understood how rich our type system is.
>

Cool, thanks!

BTW there is a somewhat parallel discussion on this gist patch in
pgsql-bugs which you may miss
https://www.postgresql.org/message-id/flat/3dda6945-c147-5afc-7720-38ec6848dafa%40gmail.com#9be5b8a75c4921498748514cb77c6e68

The main point is that buffering build is better to be enforced with
buffering=on
as otherwise buffering build becomes hard to test in the presence of sort
support.

-- 
Best regards,
Pavel Borisov

Postgres Professional: http://postgrespro.com <http://www.postgrespro.com>

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.