Subject: Re: PostgreSQL 12: Feature Highlights
References: <830415f7-78ec-ef7b-0f73-0e810ef87f91@postgresql.org>
 <f6225733-51c7-55a3-94fa-0a9f1d4a81eb@postgresql.org>
 <eab862c2-033f-56a8-198f-18427f599096@lab.ntt.co.jp>
 <CAKJS1f-pCFYGq1-go+ZyAR3GisQo-nTD=7E8ykk7Zqm9w+-OkA@mail.gmail.com>
From: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Message-ID: <e19c41f2-0c6a-dd0b-6289-4319005861b6@lab.ntt.co.jp>
Date: Wed, 15 May 2019 17:36:32 +0900
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.6.1
MIME-Version: 1.0
In-Reply-To: 
 <CAKJS1f-pCFYGq1-go+ZyAR3GisQo-nTD=7E8ykk7Zqm9w+-OkA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: "Jonathan S. Katz" <jkatz@postgresql.org>,
        pgsql-advocacy@lists.postgresql.org
Precedence: bulk

Hi David,

On 2019/05/15 11:59, David Rowley wrote:
> Sadly, they can't refer to the release notes for more information
> since they don't detail what's changed in this area :(

Bruce seemed to insist on summarizing all the performance-related
improvements into one item.  Initial wording mentioned just pruning, which
after some back and forth has finally been turned into:

  Improve performance of many operations on partitioned tables
  (Amit Langote, David Rowley, Tom Lane, Álvaro Herrera)

  Tables with thousands of child partitions can now be processed
  efficiently by operations that only need to touch a small number of
  partitions.

I hear you saying that the description may be too vague *for release
notes* even though it now covers *all* the performance improvements made
to address the use cases where small number of partitions are touched.
Maybe, you're saying that we should've mentioned individual items
(partition pruning, tuple routing, etc.) at least in the release notes,
which I did suggest on -committers [1], but maybe Bruce didn't think it
was necessary to list up individual items.

That leaves a few other commits mentioned in the release-12.sgml next to
this item that are really not related to this headline description, which
both you and I have pointed out in different threads [2][3], but I haven't
really caught Bruce's position about them.

Thanks,
Amit

[1]
https://www.postgresql.org/message-id/d5267ae5-bd4a-3e96-c21b-56bfa9fec7e8%40lab.ntt.co.jp

[2]
https://www.postgresql.org/message-id/3f0333be-fd32-55f2-9817-5853a6bbd233%40lab.ntt.co.jp

[3]
https://www.postgresql.org/message-id/CAKJS1f8R6DC45bauzeGF-QMaQ90B_NFSJB9mvVOuhKVDkajehg%40mail.gmail.com