Re: Yet another fast GiST build
x4mmm@yandex-team.ru
From: Andrey Borodin <x4mmm@yandex-team.ru>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Peter Geoghegan <pg@bowt.ie>, Tom Lane <tgl@sss.pgh.pa.us>, Justin Pryzby <pryzby@telsasoft.com>, Darafei Komяpa Praliaskouski <me@komzpa.net>, Pavel Borisov <pashkin.elfe@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, Michael Paquier <michael@paquier.xyz>, Alexander Korotkov <a.korotkov@postgrespro.ru>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Ibrar Ahmed <ibrar.ahmad@gmail.com>
Date: 2021-05-07T13:05:41Z
Lists: pgsql-hackers
Attachments
- v7-0001-Add-sortsupport-for-gist_btree-opclasses-for-fast.patch (application/octet-stream) patch v7-0001
- v7-0002-Remove-DEBUG1-verification-of-the-fact-that-index.patch (application/octet-stream) patch v7-0002
- v7-0003-Fix-varlen-keys-sorting.patch (application/octet-stream) patch v7-0003
Thanks for the investigation, Heikki.
> 8 апр. 2021 г., в 01:18, Heikki Linnakangas <hlinnaka@iki.fi> написThe correct pattern would be something like this (without the debugging NOTICE, of course):
>
>> static int
>> gbt_text_sort_build_cmp(Datum a, Datum b, SortSupport ssup)
>> {
>> GBT_VARKEY_R ra = gbt_var_key_readable((GBT_VARKEY *) PG_DETOAST_DATUM(a));
>> GBT_VARKEY_R rb = gbt_var_key_readable((GBT_VARKEY *) PG_DETOAST_DATUM(b));
>> int x = DatumGetInt32(DirectFunctionCall2Coll(bttextcmp,
>> ssup->ssup_collation,
>> PointerGetDatum(a),
>> PointerGetDatum(b)));
>> elog(NOTICE, "cmp: %s vs %s: %d",
>> TextDatumGetCString(ra.lower),
>> TextDatumGetCString(rb.lower),
>> x);
>> return x;
>> }
>
In this pattern I flipped PointerGetDatum(a) to PointerGetDatum(ra.lower), because it seems to me correct. I've followed rule of thumb: every sort function must extract and user "lower" somehow. Though I suspect numeric a bit. Is it regular varlena?
PFA patchset with v6 intact + two fixes of discovered issues.
Thanks!
Best regards, Andrey Borodin.
Commits
-
Add sortsupport for gist_btree opclasses, for faster index builds.
- 9f984ba6d23d 14.0 landed
-
pageinspect: Fix relcache leak in gist_page_items().
- 04eb75e783ba 14.0 landed
-
Fix test failure with wal_level=minimal.
- 5abca4b1cd71 14.0 landed
-
Enhance nbtree index tuple deletion.
- d168b666823b 14.0 cited
-
Fix portability issues in the new gist pageinspect test.
- 6ecaaf810b8b 14.0 landed
-
Add functions to 'pageinspect' to inspect GiST indexes.
- 756ab29124d7 14.0 landed
-
Fix missing validation for the new GiST sortsupport functions.
- 6f0bc5e1daf0 14.0 landed
-
Fix compilation warning in xlog.c
- 0a3c864c3275 14.0 cited
-
Set right-links during sorted GiST index build.
- 265ea567852a 14.0 landed
-
Fix checksum calculation in the new sorting GiST build.
- c47a240fe6db 14.0 landed
-
Add support for building GiST index by sorting.
- 16fa9b2b30a3 14.0 landed