public inbox for [email protected]  

help / color / mirror / Atom feed

From: Nathan Bossart <[email protected]>
To: [email protected]
To: [email protected]
Subject: Re: BUG #19407: pg_dump : DROP RULE creates forward references
Date: Fri, 13 Feb 2026 16:16:59 -0600
Message-ID: <aY-i27nIktxwhAww@nathan> (raw)
In-Reply-To: <aY-Q4met3RVF08LP@nathan>
References: <[email protected]>
	<aY-Q4met3RVF08LP@nathan>

On Fri, Feb 13, 2026 at 03:00:18PM -0600, Nathan Bossart wrote:
> On Fri, Feb 13, 2026 at 09:02:37AM +0000, PG Bug reporting form wrote:
>> During dump / restore with pg_dump / psql, I encounter a dependency ordering
>> issue that breaks the import when using ON_ERROR_STOP=on.
>> 
>> Problem: pg_dump executes DROP RULE for specific views, forcing them to be
>> recreated before their dependencies (custom types, collations) exist in the
>> dump file, causing import failures.
> 
> I think this is an even simpler reproducer:
> 
> 	create type t as enum ('a', 'b');
> 	create table tt (a t primary key, b text);
> 	create view v as select * from tt group by a;
> 
> Commit d8c05aff56 [0] did some work in this area, but this issue may even
> predate that.  In any case, it seems like pg_dump needs to create the type
> before it creates the dummy view to deal with circular dependencies.

After some further investigation, I found this discussion from 2022 that
mentions the same problem:

    https://postgr.es/m/flat/b43e03eb-3997-700e-c2d4-92c31e4e31ee%40dalibo.com

This led to commit 75af0f401f, which added some clarity to the
documentation for pg_dump's --clean and --if-exists options, but AFAICT we
don't actually say that using --if-exists with --clean is _not_ guaranteed
to prevent all errors due to nonexistent objects.  Perhaps we should add
that information.  I haven't looked into what it would take to actually fix
this issue, but from reading around I get the idea that it might not be
straightforward.

-- 
nathan

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected]
  Subject: Re: BUG #19407: pg_dump : DROP RULE creates forward references
  In-Reply-To: <aY-i27nIktxwhAww@nathan>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox