From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
cc: Etsuro Fujita <etsuro.fujita@gmail.com>, dacherny@gmail.com,
        PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: BUG #16631: postgres_fdw tries to insert into generated columns
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Comments: In-reply-to Peter Eisentraut <peter.eisentraut@enterprisedb.com>
	message dated "Wed, 07 Jul 2021 10:44:58 +0200"
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Date: Wed, 07 Jul 2021 11:54:19 -0400
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Peter Eisentraut <peter.eisentraut@enterprisedb.com> writes:
> On 07.07.21 09:20, Etsuro Fujita wrote:
>> * Modified nodeModifyTable.c and copyfrom.c so that they don't compute
>> generated columns for FDWs anymore.

> I don't agree with that change.  What is the point of declaring a 
> generated column on a foreign table if you ignore it?  Then you might as 
> well prohibit declaring such columns in the first place.

Maybe what we need here is some documentation clarifying exactly what
the point of a generated column on a foreign table actually *is*.
When would you do it, and what relationship if any has it got to the
generation status of the underlying remote column?

			regards, tom lane