Re: First draft of PG 17 release notes

Bruce Momjian <bruce@momjian.us>

From: Bruce Momjian <bruce@momjian.us>
To: David Rowley <dgrowleyml@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Melanie Plageman <melanieplageman@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2024-05-23T02:01:51Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Revert support for ALTER TABLE ... MERGE/SPLIT PARTITION(S) commands

  2. When creating materialized views, use REFRESH to load data.

  3. Revert temporal primary keys and foreign keys

  4. Avoid needless large memcpys in libpq socket writing

  5. Enhance nbtree ScalarArrayOp execution.

  6. Introduce a non-recursive JSON parser

  7. Combine freezing and pruning steps in VACUUM

  8. Allow SIGINT to cancel psql database reconnections.

  9. Provide API for streaming relation data.

  10. Add hash support functions and hash opclass for contrib/ltree.

  11. Pull up ANY-SUBLINK with the necessary lateral support.

  12. Read WAL directly from WAL buffers.

  13. Introduce the dynamic shared memory registry.

  14. Add macros for looping through a List without a ListCell.

  15. Support +/- infinity in the interval data type.

  16. Extend ALTER OPERATOR to allow setting more optimization attributes.

  17. Consider cheap startup paths in add_paths_to_append_rel

On Thu, May 23, 2024 at 01:34:10PM +1200, David Rowley wrote:
> On Thu, 23 May 2024 at 10:04, Bruce Momjian <bruce@momjian.us> wrote:
> > You might have seen in this thread, I do record commits that speed up
> > workloads that are user-visible, or specifically make new workloads
> > possible.  I assume that covers the items above, though I have to
> > determine this from the commit message.
> 
> It sometimes is hard to write something specific in the commit message
> about the actual performance increase.
> 
> For example, if a commit removes an O(N log2 N) algorithm and replaces
> it with an O(1), you can't say there's an X% increase in performance
> as the performance increase depends on the value of N.
> 
> Jelte did call me out for not mentioning enough detail about the
> performance in c4ab7da60, but if I claimed any % of an increase, it
> would have been specific to some workload.
> 
> What is the best way to communicate this stuff so it's easily
> identifiable when you parse the commit messages?

This is why I think we need an "Internal Performance" section where we
can be clear about simple scaling improvements that might have no
user-visible explanation.  I would suggest putting it after our "Source
code" section.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.