Horton

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

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

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From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: James Coleman <jtc331@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, 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>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Andreas Karlsson <andreas@proxel.se>
Date: 2020-05-09T22:19:45Z
Lists: pgsql-hackers 
On Sat, May 09, 2020 at 10:50:12PM +0200, Tomas Vondra wrote:
>On Sat, May 09, 2020 at 03:18:36PM -0500, Justin Pryzby wrote:
>>Checking if it's possible to address this Opened Item before 13b1.
>>
>>https://wiki.postgresql.org/wiki/PostgreSQL_13_Open_Items
>>consistency of explain output: two spaces, equals vs colons, semicolons (incremental sort)
>>
>
>Yes. Now that the other items related to incremental sort are fixed,
>this is next on my TODO.
>

OK, so aside from the typo/comment fixes, the proposed changes to the
explain format are:

  - two spaces to separate groups of related values
  - use colons rather than equals for fields
  - don't use semicolons
  - split full-groups and prefix-groups to separate lines

I'm generally OK with most of this - I'd probably keep the single-line
format, but I don't feel very strongly about that and if others think
using two lines is better ...

Barring objections I'll get this polished and pushed soon-ish (say,
early next week).


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.