Horton

Re: First draft of the PG 15 release notes (sorting)

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2022-05-11T22:38:42Z
Lists: pgsql-hackers 
On Wed, 11 May 2022 at 14:38, Justin Pryzby <pryzby@telsasoft.com> wrote:
> I wonder if this is also relevant.
>
> 65014000b35 Replace polyphase merge algorithm with a simple balanced k-way merge.

Thanks for highlighting that. It very much is relevant. In fact, it
seems to account for most of the 25% I mentioned.  That particular
test was sorting 10 million tuples with 4MB of work_mem.

I think that "Improve sorting performance (Heikki Linnakangas)" should
be moved out from "E.1.3.1.2. Indexes" and put below "E.1.3.1.4.
General Performance"

The text likely should include the words "disk-based" so that it's
clear that it's not the same as the other line about "in-memory
sorts".  I'd also be open to just having a single line too. I'd vote
to put Heikki's name first if we did that.

Maybe:

* Improve performance of sorting tuples (Heikki Linnakangas, Ronan
Dunklau, David Rowley, Thomas Munro)

This improves the merging performance of individual on-disk sort
batches, reduces memory consumption for in-memory sorts and reduces
CPU overheads for certain in-memory sorts.

David

Commits

  1. Doc: last minute adjustment to the release notes

  2. Doc: more tweaking of v15 release notes.

  3. Doc: further adjust notes about pg_upgrade_output.d.

  4. Doc: add list of major features to the v15 release notes.

  5. relnotes: update item about public schema permission change

  6. relnotes: update ordered partition scan item

  7. relnotes: add Heikki to UTF8 item

  8. relnotes: improve UTF8 text item in relation to ASCII

  9. relnotes: add null logical replication item

  10. relnotes: adjust several logical replication items and FK text

  11. relnotes: mention non-exclusive backup mode was deprecated

  12. relnotes: add author to in-memory sorts item

  13. relnotes: update for non-exclusive backup mode removal

  14. relnote: improve sorting entries

  15. relnotes: adjustments from Álvaro Herrera

  16. relnotes: update foreign key partition and add sort items

  17. relnotes: more adjustments

  18. relnotes: logical replication permissions checked by subscrib.

  19. relnotes: adjustments

  20. relnotes: remove sequence replication and update 'postgres -C'

  21. relnote: extensive updates

  22. relnotes: "training" -> "trailing"

  23. Standardize references to Zstandard as <productname>

  24. pgstat: Update docs to match the shared memory stats reality.

  25. Raise a WARNING for missing publications.

  26. Skip empty transactions for logical replication.

  27. Optionally disable subscriptions on error.

  28. Allow root-owned SSL private keys in libpq, not only the backend.

  29. Use COPY FREEZE in pgbench for faster benchmark table population.