Re: PostgreSQL 17 release announcement draft

I'll send one more bigger email. I also have made these as comments in a
google doc I'm happy to add anyone to if they're interested. Let me know.

> PostgreSQL 17 extends its performance gains to query execution. Planner
statistics help PostgreSQL to determine the best way to search for data,
and PostgreSQL 17 can now use planner statistics and the sort order [common
table expressions](https://www.postgresql.org/docs/17/queries-with.html
<https://www.google.com/url?q=https://www.postgresql.org/docs/17/queries-with.html&sa=D&source=docs&ust=1725564996929209&usg=AOvVaw1sY98EkQgjdM1C3TnVJWeu>)
([`WITH` queries](https://www.postgresql.org/docs/17/queries-with.html
<https://www.google.com/url?q=https://www.postgresql.org/docs/17/queries-with.html&sa=D&source=docs&ust=1725564996929307&usg=AOvVaw04OERMJyQuT64QbaPrZ2xa>))
to further speed up queries.

Was that meant to be the sort order "from" CTEs? Maybe a missing "From"?

> to support more expressive JSON processing capabilities and
implementation of the SQL/JSON standard.

Was that meant to be something like "and to expand the implementation" of
or "an expanded implementation"?

> "with an emphasis of converting JSON data to a native PostgreSQL data
type"

Was that meant to be an emphasis "*on" and not "of"* ?

> For the merge section, here's a proposed reworked version:

PostgreSQL 17 provides expanded control over `MERGE` behavior, including a
new `merge_action` function that describes how a row was modified.

PostgreSQL 17 provides new capabilities and performance improvements for
bulk data loading and exporting. This includes improving exports of large
rows by up to 2x using the [`COPY`](
https://www.postgresql.org/docs/17/sql-copy.html
<https://www.google.com/url?q=https://www.postgresql.org/docs/17/sql-copy.html&sa=D&source=docs&ust=1725566138606705&usg=AOvVaw02c3_7C8miH9bXrt4qopvi>)
command, and performance improvements for cases when the source and
destination encodings match. A new option `ON_ERROR` was added which can be
used to allow imports to continue even when errors happen for inserts.

> For the predefined role, something to consider would be using action
verbs. I don't know if this seems too inconsistent though. It makes it
easier to write. For example:

Use the new `pg_maintain` [predefined role](
https://www.postgresql.org/docs/17/predefined-roles.html
<https://www.google.com/url?q=https://www.postgresql.org/docs/17/predefined-roles.html&sa=D&source=docs&ust=1725566387873658&usg=AOvVaw2EZeIkeRHXpUh5Kg4WDg1v>)
to grant permissions for maintenance operations.

> For the EXPLAIN enhancements:

PostgreSQL 17 [`EXPLAIN`](
https://www.postgresql.org/docs/17/sql-explain.html
<https://www.google.com/url?q=https://www.postgresql.org/docs/17/sql-explain.html&sa=D&source=docs&ust=1725566534658961&usg=AOvVaw24h7LPwl2fAuT8qeYJn37n>)
now shows the time spent for I/O block reads and writes, and includes two
new options: `SERIALIZE` and `MEMORY`, useful for seeing the time spent in
data conversion for network transmission, and how much memory was used.

That's all I've got.

This is an exciting release! Nice work!

On Thu, Sep 5, 2024 at 1:44 PM Andrew Atkinson <andyatkinson(at)gmail(dot)com>
wrote:

> Additional chunk:
>
> Proposed:
> PostgreSQL 17 improves the performance of queries with `IN` clauses that
> use [B-tree](
> https://www.postgresql.org/docs/17/indexes-types.html#INDEXES-TYPES-BTREE)
> indexes, the default index method in PostgreSQL). Support for parallel
> index builds were added for [BRIN](
> https://www.postgresql.org/docs/17/brin.html) indexing.
>
> PostgreSQL 17 leverages the constraints you've defined. The query planner
> removes redundant `IS NOT NULL` statements when a column has a `NOT NULL`
> constraint, and skips over `IS NULL` clauses for columns with an `IS NOT
> NULL` constraint.
>
>
> On Thu, Sep 5, 2024 at 11:58 AM Andrew Atkinson <andyatkinson(at)gmail(dot)com>
> wrote:
>
>> The write operations seem to be under-sold here! These seem very exciting
>> and would be beneficial to all Postgres databases I've worked on.
>>
>> Is this a fair way to reduce the three items mentioned, as much as
>> possible? I'm not proposing they change, but just sort of pushing on
>> building down the items tied to their benefit to the end user as much as
>> possible. Possibly shortening them and making them punchier will help.
>>
>> Faster Write throughput:
>> - "Fewer WAL locks shorter lock lengths" (check this, I'm making it up,
>> but I'm wondering if it's fewer WAL locks, or the locks are held for less
>> time), thus better throughput
>> - "Faster Sequential scans" - is the benefit that they're faster?
>> - "Faster ANALYZE" - is it that ANALYZE runs faster on 17 vs. the same
>> operation on 16?
>>
>> The last point "Allowing extensions to be integrated further." I didn't
>> grab on to as much. I'm wondering if it's something like "new write
>> operation APIs are now available for extension creators" or something like
>> that?
>>
>> On Thu, Sep 5, 2024 at 11:49 AM Andrew Atkinson <andyatkinson(at)gmail(dot)com>
>> wrote:
>>
>>> Hi Jonathan. Do you want change proposals here as text snippets in
>>> emails? It seems the patch process isn't used here.
>>>
>>> If so, here's an attempted reduction that echoes what Robert said. I
>>> also thought explaining Vacuum wouldn't be necessary for this audience, so
>>> less lead-in could work. Is the benefit to end users that there is less
>>> memory and CPU needed by vacuum, thus more CPU and memory is available to
>>> their foreground workload?
>>>
>>> Original:
>>> > A foundational feature of PostgreSQL is [vacuum](
>>> https://www.postgresql.org/docs/17/routine-vacuuming.html) which is
>>> used to reclaim storage from data that was marked as removed. Reducing
>>> resources required for vacuuming directly helps other areas of PostgreSQL,
>>> particularly on very busy systems. PostgreSQL 17 introduces a new internal
>>> memory structure for vacuum that's shown up to a 20x reduction in memory
>>> and improvements in overall vacuuming speed.
>>>
>>> Proposed:
>>> The PostgreSQL [vacuum](
>>> https://www.postgresql.org/docs/17/routine-vacuuming.html) process is
>>> critical for healthy operations, requiring server instance resources to
>>> operate. With PostgreSQL 17, a new internal memory structure for vacuum was
>>> used that consumes up to 20x less memory. This improves vacuum speed and
>>> also reduces the use of shared resources, making more available for your
>>> workload.
>>>
>>>
>>> Something along those lines, where the benefit to the user is they could
>>> expect more CPU/mem etc. available for their SQL operations, right? This
>>> could be something folks want to benchmark as well as a reason to upgrade,
>>> at least for Vacuum-intensive workloads, high UPDATE and DELETE operations
>>> etc.
>>>
>>>
>>>
>>>
>>>
>>> On Thu, Sep 5, 2024 at 11:04 AM Robert Haas <robertmhaas(at)gmail(dot)com>
>>> wrote:
>>>
>>>> On Thu, Sep 5, 2024 at 5:22 AM Peter Eisentraut <peter(at)eisentraut(dot)org>
>>>> wrote:
>>>> > On 04.09.24 23:05, Jonathan S. Katz wrote:
>>>> > > Attached is the draft of the PostgreSQL 17 release announcement.
>>>> This is
>>>> > > a draft of the text that will go into the press kit, with the key
>>>> > > portions to review starting from the top of the document, up until
>>>> the
>>>> > > "About PostgreSQL" section.
>>>> >
>>>> > I noticed that we don't yet have a list of major features in the PG17
>>>> > release notes. We should probably put that in soon, so that what we
>>>> > list there and what is in the announcement are consistent.
>>>>
>>>> +1.
>>>>
>>>> > On the actual list, there will be lots of opinions to be had, but I'll
>>>> > just offer one: I don't think the MERGE RETURNING clause deserves
>>>> twice
>>>> > as much space as incremental backup.
>>>>
>>>> I agree with that, although obviously I'm biased.
>>>>
>>>> I also feel like this whole thing could just be shorter. If it were
>>>> half as long and mentioned fewer things and those more briefly, would
>>>> we be worse off? I think we might be better off, because it just feels
>>>> wordy to me right now. For example:
>>>>
>>>> A foundational feature of PostgreSQL is
>>>> [vacuum](https://www.postgresql.org/docs/17/routine-vacuuming.html),
>>>> which is used to reclaim storage from data that was marked as removed.
>>>> Reducing resources required for vacuuming directly helps other areas
>>>> of PostgreSQL, particularly on very busy systems. PostgreSQL 17
>>>> introduces a new internal memory structure for vacuum that's shown up
>>>> to a 20x reduction in memory and improvements in overall vacuuming
>>>> speed. This release also removes the `1GB` limit on the memory it can
>>>> use (controlled by
>>>> [`maintenance_work_mem`](
>>>> https://www.postgresql.org/docs/17/runtime-config-resource.html#GUC-MAINTENANCE-WORK-MEM)
>>>> ),
>>>> letting users apply more resources to vacuuming, which is beneficial
>>>> for systems with lots of changes.
>>>>
>>>> It seems to me that the first two sentences could just be completely
>>>> nuked, and everything from "letting users" to the end could also be
>>>> nuked. At least to me, all of that stuff reads as unnecessarily
>>>> filler. I'm not at all sure that removing the 1GB limit on
>>>> maintenance_work_mem is important enough that it needs to be in the
>>>> release announcement -- I agree it's a good improvement, but to have
>>>> it be one of the first things in the press release seems like an odd
>>>> choice from my perspective. Nobody's going to look back on this
>>>> release years from now and say "oh, that was the release where could
>>>> finally set maintenance_work_mem=4GB, that was so much better". If
>>>> they think about VACUUM, they'll think about the 20x memory reduction
>>>> stuff which made the ability to configure values larger than 1GB
>>>> irrelevant in the first place. So I'd probably delete the part about
>>>> lifting the 1GB cap entirely. But even if you don't do that, the
>>>> paragraph could be half as long without losing anything, from my
>>>> perspective.
>>>>
>>>> --
>>>> Robert Haas
>>>> EDB: http://www.enterprisedb.com
>>>>
>>>>
>>>>