Horton

Re: [HACKERS] [PATCH] Incremental sort

Alexander Korotkov <a.korotkov@postgrespro.ru>

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From: Alexander Korotkov <a.korotkov@postgrespro.ru>
To: Andres Freund <andres@anarazel.de>
Cc: Teodor Sigaev <teodor@sigaev.ru>, Darafei Komяpa Praliaskouski <me@komzpa.net>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Antonin Houska <ah@cybertec.at>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-03-29T13:05:40Z
Lists: pgsql-hackers 
On Wed, Mar 28, 2018 at 7:17 PM, Andres Freund <andres@anarazel.de> wrote:

> On 2018-03-28 16:28:01 +0300, Teodor Sigaev wrote:
> > > BTW, patch had conflicts with master.  Please, find rebased version
> attached.
> >
> > Despite by patch conflist patch looks commitable, has anybody objections
> to
> > commit it?
>
> > Patch recieved several rounds of review during 2 years, and seems to me,
> > keeping it out from sources may cause a lost it. Although it suggests
> > performance improvement in rather wide usecases.
>
> My impression it has *NOT* received enough review to be RFC. Not saying
> it's impossible to get there this release, but that just committing it
> doesn't seem wise.
>

I would say that executor part of this patch already received plenty of
review.
For sure, there still might be issues.  I just mean that amount of review of
executor part of this patch is not less than in average patch we commit.
But optimizer and costing part of this patch still need somebody to take
a look at it.

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

Commits

  1. Further adjustments to Hashagg EXPLAIN ANALYZE output

  2. Rework EXPLAIN format for incremental sort

  3. Fix typos and improve incremental sort comments

  4. Stabilize incremental_sort tests

  5. Minor improvements in Incremental Sort explain

  6. Consider Incremental Sort paths at additional places

  7. Fix representation of SORT_TYPE_STILL_IN_PROGRESS.

  8. Fix failures in incremental_sort due to number of workers

  9. Fix show_incremental_sort_info with force_parallel_mode

  10. Implement Incremental Sort

  11. Fix handling of "Subplans Removed" field in EXPLAIN output.

  12. Fix EXPLAIN (SETTINGS) to follow policy about when to print empty fields.

  13. Ensure plpgsql result tuples have the right composite type marking.

  14. Propagate sort instrumentation from workers back to leader.

  15. Make new regression test case parallel-safe, and improve its output.

  16. Push limit through subqueries to underlying sort, where possible.

  17. Fix inappropriate printing of never-measured times in EXPLAIN.

  18. Fix some infelicities in EXPLAIN output for parallel query plans.