Feedback-ID: ie3de48e3:Fastmail
Date: Tue, 27 May 2025 17:07:12 +0200
From: =?utf-8?Q?=C3=81lvaro?= Herrera <alvherre@kurilemu.de>
To: Mahdi Bahrami <pgsql@mahdibm.com>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: Database creation performance drop going from pg 14 to pg 15+
Message-ID: <202505271507.xvfbdztae74a@alvherre.pgsql>
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On 2025-May-27, Mahdi Bahrami wrote:

> Here's how I ran the commands that seem to be at fault when using
> PostgresNIO. I only ran the drop-db create-db commands, not the whole
> chain, which should still be sufficient:
> ```
> PGPASSWORD=xxx psql -U spi_test -h 127.0.0.1 postgres -c "DROP DATABASE IF EXISTS spi_test WITH (FORCE);" -c "CREATE DATABASE spi_test;"
> ```

I wonder if this is related to the change to CREATE DATABASE in release 15.
Maybe you could test this with "CREATE DATABASE spi_test STRATEGY =
file_copy;" and see if that returns it to the original performance.
The new strategy is allegedly faster, but maybe in your case, for
whatever reason, it isn't.

I do wonder why is the database drop/create performance so critical,
though.  I mean, surely there are more relevant performance problems to
be concerned about.

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
"Tiene valor aquel que admite que es un cobarde" (Fernandel)