Message-ID: <5bc9737f-14d6-9c1b-ba93-907bbaada24d@postgrespro.ru>
Date: Tue, 18 Jul 2023 14:19:46 +0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Subject: Re: Add TOAST support for more system tables
Content-Language: en-US
To: tgl@sss.pgh.pa.us
References: <c5b7d324-0201-64a5-649b-24a78bce5224@postgrespro.ru>
 <4092511.1689633064@sss.pgh.pa.us> <ZLYj+IwSyyYw8Cu4@paquier.xyz>
From: Sofia Kopikova <s.kopikova@postgrespro.ru>
Cc: dgrowleyml@gmail.com, michael@paquier.xyz, pgsql-hackers@postgresql.org
In-Reply-To: <ZLYj+IwSyyYw8Cu4@paquier.xyz>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Archived-At: <https://www.postgresql.org/message-id/5bc9737f-14d6-9c1b-ba93-907bbaada24d%40postgrespro.ru>
Precedence: bulk

On Mon, Jul 17, 2023 at 06:31:04PM -0400, Tom Lane wrote:

> Sofia Kopikova <s.kopikova@postgrespro.ru> writes:
>> This patch adds TOAST support for system tables pg_class,
>> pg_attribute and pg_largeobject_metadata, as they include ACL columns,
>> which may be potentially large in size.
> We have been around on this topic before, cf discussion leading up to
> commit 96cdeae07.  Allowing toasted data in pg_class or pg_attribute
> seems quite scary to me because of the potential for recursive access,
> particularly during cache-flush scenarios.  (That is, you need to be
> able to read those catalogs on the way to fetching a toasted value,
> so how can you be sure that doesn't devolve into an infinite loop?)
Many thanks for your reviews. I'm gonna do research and revise this
feature thoroughly.

I'll set status of the patch to "Waiting on author" for now.

--
Sofia Kopikova
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company