Date: Thu, 7 Nov 2019 11:20:32 +0200
From: Eugen Konkov <kes-kes@yandex.ru>
Message-ID: <1771593631.20191107112032@yandex.ru>
To: Bruce Momjian <bruce@momjian.us>
CC: PostgreSQL-development <pgsql-hackers@postgreSQL.org>,
 pgsql-docs@lists.postgresql.org
Subject: Re: Does 'instead of delete' trigger support modification of OLD
In-Reply-To: <20191106185935.GE1843@momjian.us>
References: <919823407.20191029175436@yandex.ru>
 <20191106185935.GE1843@momjian.us>
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> I looked in the CREATE TRIGGER manual page and found this:

>         https://www.postgresql.org/docs/12/sql-createtrigger.html
>         If the trigger fires before or instead of the event, the trigger
>         can skip the operation for the current row, or change the row
>         being inserted (for INSERT and UPDATE operations only).

> I don't see the "(for INSERT and UPDATE operations only)" language in
> the main trigger documentation,
> https://www.postgresql.org/docs/current/trigger-definition.html.  I have
> written the attached patch to fix that.  Does that help?

No.   If   we document that PG does not allow to modify OLD at instead
of  trigger,  the  we can not implement that. Probably we can put note
that  "currently  modification of the trigger row for RETURNING is not
implemented"

> As far as allowing DELETE to modify the trigger row for RETURNING, I am
> not sure how much work it would take to allow that, but it seems like it
> is a valid requite, and if so, I can add it to the TODO list.

Yes,  Add please into TODO the feature to "allowing DELETE to modify the trigger row
for  RETURNING".  Becuase, as I have described at first letter, without
this the RETURNING rows **does not correspond actually deleted data**

Thank you.

-- 
Best regards,
Eugen Konkov