From: Mladen Gogala <gogala.mladen@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: Catching up with performance & PostgreSQL 15
Date: Tue, 29 Nov 2022 09:17:48 -0500
Message-ID: <401ac59b-067f-28f2-547d-417ee5c49c39@gmail.com> (raw)
In-Reply-To: <20221129083615.fseqfvd5svtjbrb6@alvherre.pgsql>
References: <20221129083615.fseqfvd5svtjbrb6@alvherre.pgsql>
On 11/29/22 03:36, Alvaro Herrera wrote:
> On 2022-Nov-28, Mladen Gogala wrote:
>
>> As for JIT, I've recently asked that question myself. I was told that
>> PostgreSQL with LLVM enabled performs approximately 25% better than without
>> it.
> Hmm, actually, normally you're better off turning JIT off, because it's
> very common to diagnose cases of queries that become much, much slower
> because of it. Some queries do become faster, but it's not a wide
> margin, and it's not a lot. There are rare cases where JIT is
> beneficial, but those tend to be queries that take upwards of several
> seconds already.
>
> IMO it was a mistake to turn JIT on in the default config, so that's one
> thing you'll likely want to change.
>
Hmmm, I think I will run pgbench with and without JIT on and see the
difference.
--
Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com
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To: pgsql-performance@postgresql.org
Cc: gogala.mladen@gmail.com, alvherre@alvh.no-ip.org, pgsql-performance@lists.postgresql.org
Subject: Re: Catching up with performance & PostgreSQL 15
In-Reply-To: <401ac59b-067f-28f2-547d-417ee5c49c39@gmail.com>
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