Horton

Re: First draft of PG 17 release notes

Jelte Fennema-Nio <postgres@jeltef.nl>

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From: Jelte Fennema-Nio <postgres@jeltef.nl>
To: Andres Freund <andres@anarazel.de>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Bruce Momjian <bruce@momjian.us>, Melanie Plageman <melanieplageman@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2024-05-16T09:49:24Z
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, 16 May 2024 at 05:48, Andres Freund <andres@anarazel.de> wrote:
> We're having this debate every release. I think the ongoing reticence to note
> performance improvements in the release notes is hurting Postgres.
>
> For one, performance improvements are one of the prime reason users
> upgrade. Without them being noted anywhere more dense than the commit log,
> it's very hard to figure out what improved for users. A halfway widely
> applicable performance improvement is far more impactful than many of the
> feature changes we do list in the release notes.
>
> For another, it's also very frustrating for developers that focus on
> performance. The reticence to note their work, while noting other, far
> smaller, things in the release notes, pretty much tells us that our work isn't
> valued.

+1 to the general gist of listing every perf improvement **and memory
usage reduction** in the release notes. Most of them are already
grouped together in a dedicated "General performance" section anyway,
having that section be big would only be good imho to show that we're
committed to improving perf.

I think one thing would make this a lot easier though is if commits
that knowlingy impact perf would clearly say so in the commit message,
because now it's sometimes hard to spot as someone not deeply involved
with the specific patch. e.g. c4ab7da606 doesn't mention performance
at all, so I'm not surprised it wasn't listed initially. And while
667e65aac3 states that multiple rounds of heap scanning is now
extremely rare, it doesn't explicitly state what the kind of perf
impact can be expected because of that.

Maybe something like introducing a common "Perf-Improvement: true"
marker in the commit message and when doing so add a clear paragraph
explaining the expected perf impact perf impact. Another option could
be to add a "User Impact" section to the commit message, where an
author could add their suggestion for a release note entry. So
basically this suggestion boils down to more clearly mentioning user
impact in commit messages, instead of mostly/only including
technical/implementation details.