public inbox for pgsql-docs@postgresql.org  

help / color / mirror / Atom feed

From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Radoulov, Dimitre <cichomitiko@gmail.com>
To: pgsql-docs@lists.postgresql.org
Subject: Re: Documentation clarification request: pg_dumpall and Large Objects
Date: Thu, 04 Dec 2025 16:50:55 +0100
Message-ID: <d4ab85597252c7a529f64ffd5cc5b09d92504df4.camel@cybertec.at> (raw)
In-Reply-To: <CAGJBphSX2oMPPu=VM4U8NP4+qffFH_483tFQCJ_s-mOcN3DLDw@mail.gmail.com>
References: <CAGJBphSX2oMPPu=VM4U8NP4+qffFH_483tFQCJ_s-mOcN3DLDw@mail.gmail.com>

On Thu, 2025-12-04 at 13:12 +0100, Radoulov, Dimitre wrote:
> I would like to request a clarification in the pg_dumpall
> documentation regarding Large Objects (LOBs). The current
> documentation does not explicitly state whether pg_dumpall includes
> Large Objects in its output.
> 
> This behavior is clear from the implementation, but not from the
> documentation.
> 
> I propose adding an explicit note such as:
> 
>   "pg_dumpall does not include Large Objects (BLOBs). To back up
>    Large Objects, use pg_dump -b per database."

At the beginning of the "pg_dumpall" page we see:

  pg_dumpall is a utility for writing out (“dumping”) all PostgreSQL databases
  of a cluster into one script file. [...].
  It does this by calling pg_dump for each database in the cluster.

And the pg_dump documentation says:

  -b
  --large-objects
  --blobs (deprecated)

    Include large objects in the dump. This is the default behavior except when
    --schema, --table, --schema-only, --statistics-only, or --no-data is specified.

Since pg_dumpall dumps the databases (and not parts of the databases), it will
automatically dump large objects too.

But I admit that you have to go by circumstantial evidence here.  But rather
than explicitly naming large objects, perhaps it would be useful to add something
like

  pg_dumpall is primarily intended as a tool to upgrade database clusters.
  As such, it by default exports all data of the entire cluster.
  The only part of the state of a database cluster that is *not* included
  in the output of pg_dumpall are the configuration files and database parameters
  changed with ALTER SYSTEM.

Yours,
Laurenz Albe

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: pgsql-docs@postgresql.org
  Cc: laurenz.albe@cybertec.at, cichomitiko@gmail.com, pgsql-docs@lists.postgresql.org
  Subject: Re: Documentation clarification request: pg_dumpall and Large Objects
  In-Reply-To: <d4ab85597252c7a529f64ffd5cc5b09d92504df4.camel@cybertec.at>

* 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