Date: Mon, 12 Jun 2023 17:47:49 +0200 (CEST)
From: Erik Wienhold <ewie@ewie.name>
To: oliver_schmidt_@hotmail.de, pgsql-docs@lists.postgresql.org
Message-ID: <411306699.367929.1686584869079@office.mailbox.org>
In-Reply-To: 
 <168657770315.399156.14528203301769250174@wrigleys.postgresql.org>
References: <168657770315.399156.14528203301769250174@wrigleys.postgresql.org>
Subject: Re: Further clarification in documentation: No deletion of
 unreferenced large objects
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Importance: Normal
Archived-At: 
 <https://www.postgresql.org/message-id/411306699.367929.1686584869079%40office.mailbox.org>
Precedence: bulk

> On 12/06/2023 15:48 CEST PG Doc comments form <noreply@postgresql.org> wrote:
>
> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/15/datatype-binary.html
> Description:
>
> When deleting a row that references (contains) a large object, I think that
> most users expect the DBMS to take care of the, now unreferenced, BLOB. It's
> good to know that PostgreSQL handles this differently and that one must
> periodically use vacuumlo to avoid BLOB data piling up. At least, that's
> what I understood.
>
> I think a small paragraph in the documentation about this would help many
> people. I can help with writing, if needed.

bytea and large objects are two different ways of storing binary data.  vacuumlo
does not apply to bytea.  Extension lo also mentions the issue with orphan
objects already: https://www.postgresql.org/docs/15/lo.html

Some further info on bytea vs large objects:
https://www.cybertec-postgresql.com/en/binary-data-performance-in-postgresql/

--
Erik