Re: PostgreSQL 12: Feature Highlights

Bruce Momjian <bruce@momjian.us>

From: Bruce Momjian <bruce@momjian.us>
To: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: David Rowley <david.rowley@2ndquadrant.com>, Justin Clift <justin@postgresql.org>, "Jonathan S. Katz" <jkatz@postgresql.org>, pgsql-advocacy@lists.postgresql.org
Date: 2019-05-14T13:19:45Z
Lists: pgsql-hackers
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.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
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Commits

  1. doc: PG 12 relnotes, add mention of single-child optimization

  2. docs: split out sort-skip partition item in PG 12 release notes

  3. docs: update partition item in PG 12 release notes