From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pawel Veselov <pawel.veselov@gmail.com>
cc: pgsql-general@lists.postgresql.org
Subject: Re: Dump version issues
In-reply-to: <CAMnJ+Bet04kPY8KFxKA6tYaCGmxEhwvYoPZ1eGOHoVAJp=1rKA@mail.gmail.com>
References: <CAMnJ+Bet04kPY8KFxKA6tYaCGmxEhwvYoPZ1eGOHoVAJp=1rKA@mail.gmail.com>
Comments: In-reply-to Pawel Veselov <pawel.veselov@gmail.com>
	message dated "Wed, 23 Apr 2025 20:46:39 +0200"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <1435166.1745435176.1@sss.pgh.pa.us>
Date: Wed, 23 Apr 2025 15:06:16 -0400
Message-ID: <1435167.1745435176@sss.pgh.pa.us>
Archived-At: <https://www.postgresql.org/message-id/1435167.1745435176%40sss.pgh.pa.us>
Precedence: bulk

Pawel Veselov <pawel.veselov@gmail.com> writes:
> Was trying to import a database from a cloud deployment, and ran into this.

> Exported the database with:
> * pg_dump (PostgreSQL) 12.20 (Ubuntu 12.20-0ubuntu0.20.04.1)
> * RDS PostgreSQL 12.19 on x86_64-pc-linux-gnu, compiled by gcc (GCC)
> 7.3.1 20180712 (Red Hat 7.3.1-12), 64-bit

> This produced a dump file of version 1.16, at least according to 'file'.

Better take another look at which pg_dump you used.  Archive version
1.16 was introduced in PG v17, according to a quick look at the source
code.  pg_restore versions older than v17 are not going to understand
it.

> I'm not sure whether the server has any say in the version of the dump
> file, I assume it doesn't.

Nope, just pg_dump.

> So, how come older software (according to versions) produces dump
> files with a greater version
> than the newer software can understand? Is this Ubuntu package
> maintainers messing things up?

You'd have to ask them.

> Given a pg_dump, it would be nice if its "-V" output would say which
> version of the dump it would produce,
> and a pg_restore - what's the max (and min, if that's a thing) version
> of the dump that it will accept.

Hmm, maybe.  The original thought was that the archive version would
seldom be a limiting factor: it describes the file format but not the
SQL inside the file, and that's often version-specific too.  So in
general we don't promise that pg_dump version N will produce output
that you can use with pg_restore or server versions less than N,
whether they share the same archive version or not.

			regards, tom lane