Re: pgsql: docs: fist draft version of the PG 12 release notes

On 2019/05/11 10:25, Bruce Momjian wrote:
> I struggled to talk about partitioning since there were so many
> improvements. I favored a more generic item that just suggested
> dramatic improvements. I have modified the text to:
>
> Improve performance of many operations on partitioned tables (Amit
> Langote, David Rowley, Tom Lane, Álvaro Herrera)
>
> Also, thousands of partitions can now be pruned efficiently.
>
> Committed.

Thanks.

> Does that work?

That's better, but the second line still just mentions pruning efficiency.
It's true that pruning large number of partitions got a lot quicker in
this release, but that is by no means the only improvement. How about
writing:

Thousands of partitions can now be pruned efficiently. Also, inserting
into partitioned tables no longer slows down as the number of partitions
increases.

or some such.

Also, as David said on -advocacy [1] regarding pruning, it's not really
that the core "pruning" algorithm itself was improved in this release.
Speed-up came from reworking planner's (and to some extent executor's) use
of the pruning functionality to be more efficient. But maybe it's fine to
use the word "pruning" in the release notes to indicate that this speedup
is only meaningful workloads that benefit from it.

Thanks,
Amit

[1]
https://www.postgresql.org/message-id/CAKJS1f-1%3DBoVkJaTnfb87nrVUFLprdc7smsBsF5MGyCXnNivzw%40mail.gmail.com