Horton

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

James Coleman <jtc331@gmail.com>

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From: James Coleman <jtc331@gmail.com>
To: Shaun Thomas <shaun.thomas@2ndquadrant.com>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2019-05-31T15:29:24Z
Lists: pgsql-hackers 
On 2018-06-01 14:22:26, Alexander Korotkov wrote:
> I'd like to note, that I'm going to provide revised version of this patch
> to the next commitfest.
> After some conversations at PGCon regarding this patch, I got more
> confident that providing separate paths for incremental sorts is right.
> In the next revision of this patch, incremental sort paths would be
> provided in more cases.

Alexander,

I'm currently rebasing the patch, and if I get some time I'm going to
look into working on it.

Would you be able to provide a bit more detail on the changes you were
hoping to make after conversations you'd had with others? I'm hoping
for any pointers/context you have from those conversations as to what
you felt was necessary to get this change committed.

Thanks,
James Coleman

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.