Feedback-ID: ia2694551:Fastmail
Date: Wed, 5 Feb 2025 20:26:20 +0100
From: =?utf-8?Q?=C3=81lvaro?= Herrera <alvherre@alvh.no-ip.org>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Vladlen Popolitov <v.popolitov@postgrespro.ru>,
	Sutou Kouhei <kou@clear-code.com>, zhjwpku@gmail.com, michael@paquier.xyz,
	pgsql-hackers@postgresql.org
Subject: Re: Make COPY format extendable: Extract COPY TO format
 implementations
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On 2025-Feb-05, Masahiko Sawada wrote:

> I think that the patch needs to check if the function's result type is
> COPY_HANDLEROID by using get_func_rettype(), before calling it. But
> with this check, we can prevent arbitrary functions from being called
> via COPY. Why do we need to extend CREATE ACCESS METHOD too for that
> purpose?

It's a nicer UI than a bare CREATE FUNCTION, but perhaps it is overkill.
IIRC the reason we require CREATE ACCESS METHOD for table AMs is so that
we acquire a pg_am entry with an OID that can be referenced from
elsewhere, for instance you can't drop an AM if tables are using it; but
you can't use COPY in rules or anything like that that's going to be
stored permanently.  Perhaps you're right that we don't need this for
extensible COPY FORMAT.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/