Date: Thu, 7 Nov 2019 11:24:29 +0200
From: Eugen Konkov <kes-kes@yandex.ru>
Message-ID: <352093181.20191107112429@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: <1771593631.20191107112032@yandex.ru>
References: <919823407.20191029175436@yandex.ru>
 <20191106185935.GE1843@momjian.us>
  <1771593631.20191107112032@yandex.ru>
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Hello Eugen,

Thursday, November 7, 2019, 11:20:32 AM, you wrote:

>> 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"

sorry, typo. Please read:
"currently  modification of the trigger row for DELETE RETURNING is notimplemented"


>> 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