Horton

Re: [HACKERS] [PATCH] Incremental sort

Tomas Vondra <tomas.vondra@2ndquadrant.com>

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From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Teodor Sigaev <teodor@sigaev.ru>, Alexander Korotkov <a.korotkov@postgrespro.ru>, Alexander Kuzmenkov <a.kuzmenkov@postgrespro.ru>
Cc: Andres Freund <andres@anarazel.de>, Darafei Komяpa Praliaskouski <me@komzpa.net>, Antonin Houska <ah@cybertec.at>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-04-07T14:52:44Z
Lists: pgsql-hackers 
On 04/07/2018 04:37 PM, Teodor Sigaev wrote:
>> by this patch.  Revised version is attached.
> 
> Fine, patch got several rounds of review in all its parts. Is any
> places which should be improved before commit?
> 

I personally feel rather uneasy about committing it, TBH.

While I don't see any obvious issues in the patch at the moment, the
recent changes were rather significant so I might easily miss some
unexpected consequences. (OTOH it's true it was mostly about reduction
of scope, to limit the risks.)

I don't have time to do more review and testing on the latest patch
version, unfortunately, certainly not before the CF end.


So I guess the ultimate review / decision is up to you ...

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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.