Re: [PATCH] Incremental sort (was: PoC: Partial sort)

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

From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: James Coleman <jtc331@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Michael Paquier <michael@paquier.xyz>, Rafia Sabih <rafia.pghackers@gmail.com>, Peter Geoghegan <pg@bowt.ie>, Simon Riggs <simon@2ndquadrant.com>, Shaun Thomas <shaun.thomas@2ndquadrant.com>, Dmitry Dolgov <9erthalion6@gmail.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>, Andreas Karlsson <andreas@proxel.se>
Date: 2020-04-07T02:53:05Z
Lists: pgsql-hackers
On Mon, Apr 06, 2020 at 10:19:41PM -0400, Tom Lane wrote:
>James Coleman <jtc331@gmail.com> writes:
>> Fair enough. Unsure if Tomas is still online to comment and/or push,
>> but reverting SORT_TYPE_STILL_IN_PROGRESS back to 0 works for me as an
>> initial fix.
>
>I'm guessing he went to bed, so I'll push a fix in a moment.
>The patch has survived enough test cycles here now to make me
>moderately confident that it fixes the issue.
>

Nope, how I could I sleep with half of the buildfarm still red?

I came to the same conclusion (that the change in TuplesortMethod
definiton is the culprit) a while ago and was about to push a fix that
initialized it correctly in ExecSortInitializeDSM. But I agree reverting
it back to the old definition is probably better.

Thanks!

-- 
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.