Message-ID: <240b5c920d864da8157e65f8b7683c6a5e6d8aae.camel@cybertec.at>
Subject: Re: Does pg_dump custom format only compress the table data?
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Holger Jakobs <holger@jakobs.com>, pgsql-admin@lists.postgresql.org
Date: Tue, 03 Feb 2026 13:47:49 +0100
In-Reply-To: <6bff91db-843e-4858-95dd-cc8bfb90c012@jakobs.com>
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	 <6bff91db-843e-4858-95dd-cc8bfb90c012@jakobs.com>
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On Tue, 2026-02-03 at 08:51 +0100, Holger Jakobs wrote:
> Am 03.02.26 um 07:06 schrieb Laurenz Albe:
> > On Mon, 2026-02-02 at 10:55 -0500, Ron Johnson wrote:
> > > Out of curiosity, I opened that dump file in vim, and saw not only DD=
L strings but cleartext table data.
> > >=20
> > > Why isn't it compressed?
> > Are your DDL statement large enough that you would expect that compress=
ing
> > them would offer any real advantage?
>=20
> That wasn't the question. It was about why table DATA aren't compressed,=
=20
> but in clear text.

Ah, I see.

By default, you wouldn't see any table data, because they get compressed.

If a custom format dump is not compressed, the reason could be:

- PostgreSQL was built without support for compression (--without-zlib)

- pg_dump was called with --compress=3D0

Yours,
Laurenz Albe