Date: Wed, 20 May 2026 15:17:49 +0200
From: hubert depesz lubaczewski <depesz@depesz.com>
Sender: depesz@depesz.com
To: Ertan =?utf-8?B?S8O8w6fDvGtvZ2x1?= <ertan.kucukoglu@gmail.com>
Cc: pgsql-general@lists.postgresql.org
Subject: Re: Large backup size of pg_dump
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On Wed, May 20, 2026 at 10:17:57AM +0300, Ertan Küçükoglu wrote:
> Hello,
> 
> I am using PostgreSQL 18.4 x64 on Windows Server 2022. There is a very
> small single database in the cluster.
> 
> There are hourly pg_dump backups scheduled and database backup size is
> around 10GB.

1. pg_dump is not the best choice for backups.
2. When using pg_dump, use at least -Fd, and -jX to make the dumps work
   in parallel
3. Check what is using the most space in dump, and compare it with db
4. What exactly do you mean by "BLOB"? What is the actual datatype of
   the field?
5. What is `\l+ your_db_name` output from psql?

> I didn't understand about 2.5 times bigger backup sizes than the total
> cluster size. I do not know what to check either. Is there a way for me to
> make the hourly backup size smaller?

Consider compressing it? Or use some backup tool that handles
incremental/differential backups, like, for example, backrest.

depesz