Horton

Re: Performance degradation on concurrent COPY into a single relation in PG16.

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-07-10T15:28:25Z
Lists: pgsql-hackers 
Hi,

On 2023-07-10 15:25:41 +0200, Alvaro Herrera wrote:
> On 2023-Jul-03, Masahiko Sawada wrote:
> 
> > While testing PG16, I observed that in PG16 there is a big performance
> > degradation in concurrent COPY into a single relation with 2 - 16
> > clients in my environment. I've attached a test script that measures
> > the execution time of COPYing 5GB data in total to the single relation
> > while changing the number of concurrent insertions, in PG16 and PG15.
> 
> This item came up in the RMT meeting.  Andres, I think this item belongs
> to you, because of commit 00d1e02be2.

I'll take a look - I wasn't even aware of this thread until now.

Greetings,

Andres Freund

Commits

  1. Avoid edge case in pg_visibility test with small shared_buffers

  2. Fix bulk table extension when copying into multiple partitions

  3. hio: Take number of prior relation extensions into account

  4. Fix performance regression in pg_strtointNN_safe functions

  5. Fix performance problem with new COPY DEFAULT code

  6. hio: Use ExtendBufferedRelBy() to extend tables more efficiently

  7. Add VACUUM/ANALYZE BUFFER_USAGE_LIMIT option