Subject: Re: PostgreSQL 12: Feature Highlights
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From: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Message-ID: <8fd9a06a-8d8f-b943-0ac1-7a4d58e7b20c@lab.ntt.co.jp>
Date: Wed, 15 May 2019 09:34:10 +0900
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To: Bruce Momjian <bruce@momjian.us>
Cc: David Rowley <david.rowley@2ndquadrant.com>,
        Justin Clift <justin@postgresql.org>,
        "Jonathan S. Katz" <jkatz@postgresql.org>,
        pgsql-advocacy@lists.postgresql.org
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On 2019/05/14 22:19, Bruce Momjian wrote:
> On Tue, May 14, 2019 at 06:25:43PM +0900, Amit Langote wrote:
>> Considering the quoted discussion here, maybe it's a good idea to note
>> that only the operations that need to touch a small number of partitions
>> are now processed efficiently, which covers both SELECT/UPDATE/DELETE that
>> benefit from improved pruning efficiency and INSERT that benefit from
>> improved tuple routing efficiency.  So, maybe:
>>
>> 	Tables with thousands of child partitions can now be processed
>> 	efficiently by operations that only need to touch a small number
>>         of partitions.
>>
>> That is, as I mentioned above, as opposed to queries that need to process
>> all partitions (such as, select count(*) from partitioned_table), which
>> don't perform any faster in v12 than in v11.  The percentage of users who
>> run such workloads on PostgreSQL may be much smaller today, but perhaps
>> it's not a good idea to mislead them into thinking that *everything* with
>> partitioned tables is now faster even with thousands of partitions.
> 
> Agreed, I changed it to your wording.

Thank you.

Regards,
Amit