| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Justin Pryzby <pryzby(at)telsasoft(dot)com> |
| Cc: | Heikki Linnakangas <hlinnaka(at)iki(dot)fi>, "Andrey M(dot) Borodin" <x4mmm(at)yandex-team(dot)ru>, Darafei Komяpa Praliaskouski <me(at)komzpa(dot)net>, Pavel Borisov <pashkin(dot)elfe(at)gmail(dot)com>, Thomas Munro <thomas(dot)munro(at)gmail(dot)com>, Michael Paquier <michael(at)paquier(dot)xyz>, Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Yet another fast GiST build |
| Date: | 2020-09-20 23:06:09 |
| Message-ID: | 896113.1600643169@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Justin Pryzby <pryzby(at)telsasoft(dot)com> writes:
> This also appears to break checksums.
I was wondering about that, because the typical pattern for use of
smgrextend for indexes seems to be
RelationOpenSmgr(rel);
PageSetChecksumInplace(page, lastblock);
smgrextend(rel->rd_smgr, MAIN_FORKNUM, lastblock, zerobuf.data, false);
and gist_indexsortbuild wasn't doing either of the first two things.
gist_indexsortbuild_flush_ready_pages looks like it might be
a few bricks shy of a load too. But my local CLOBBER_CACHE_ALWAYS
run hasn't gotten to anything except the pretty-trivial index
made in point.sql, so I don't have evidence about it.
Another interesting point is that all the other index AMs seem to WAL-log
the new page before the smgrextend call, whereas this code is doing it
in the other order. I strongly doubt that both patterns are equally
correct. Could be that the other AMs are in the wrong though.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Ranier Vilela | 2020-09-20 23:09:56 | Re: Planner, check if can use consider HASH for groupings (src/backend/optimizer/plan/planner.c) |
| Previous Message | Justin Pryzby | 2020-09-20 22:44:46 | Re: Yet another fast GiST build |