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Date: Mon, 26 Mar 2018 16:17:56 +0200
From: hubert depesz lubaczewski <depesz@depesz.com>
Sender: depesz@depesz.com
To: Artem Tomyuk <admin@leboutique.com>
Cc: Keith <keith@keithf4.com>, pgsql-admin <pgsql-admin@postgresql.org>
Subject: Re: how to shrink pg_attribute table in some database
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On Mon, Mar 26, 2018 at 05:15:14PM +0300, Artem Tomyuk wrote:
> For now pg_attribute bloated to 300GB in size, and we have only 260GB's of
> free space on disk.
> In normal situation pg_attribute takes 50mb in size for our DB...
> Can we assume that if we will run vacuum full on pg_attribute it will take
> additional 50MB on disk?

You can estimate by doing:

create table z as select * from pg_Attribute;

and then checking size of z.

bloat there suggests that you have huge churn in tables - like: create
table, drop table, lots of times.

Best regards,

depesz