Feedback-ID: ie0a040ee:Fastmail
Message-ID: <ef7c466d-e3b9-4d60-bc03-cd9b48581442@eisentraut.org>
Date: Mon, 9 Sep 2024 08:02:54 +0200
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: Virtual generated columns
To: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: jian he <jian.universality@gmail.com>,
 pgsql-hackers <pgsql-hackers@postgresql.org>
References: <a368248e-69e4-40be-9c07-6c3b5880b0a6@eisentraut.org>
 <ffc0cb54-0666-4820-9baa-49d839007eef@eisentraut.org>
 <CACJufxE+E-iYmBnZVZHiYA+WpyZZVv7BfiBLpo=T70EZHDU9rw@mail.gmail.com>
 <fd6d260b-a401-4355-8688-e3bcb7e93527@eisentraut.org>
 <CACJufxGh=XX7q5xTci---HikSJsOwP7_qCNyyDHdp2YL4NLZCg@mail.gmail.com>
 <CACJufxHxoz_KVQxcQ=cSvJc+PNbh=FaHbcMZCOisoOaGAgjy4w@mail.gmail.com>
 <732a9543-0312-4f0c-a471-857b507a3546@eisentraut.org>
 <ebd1e0e9-115f-4dfa-98b8-e9b8e2f9eb2d@eisentraut.org>
 <CAEZATCV=RX0M58-uqSR6tFjwQAFnEcx3hvW-9ZZfRQJLg5LzRw@mail.gmail.com>
 <0f811f71-8c86-4e1b-b3bb-6a535674a440@eisentraut.org>
 <CAEZATCU3q=znAL7X1aSxuMpjfSyB1cT5j398HPb9ix9ci_HUqA@mail.gmail.com>
 <cd7c0fea-6c4b-4bdd-af3b-4d4dabb32ca1@eisentraut.org>
 <CAEZATCVLfMzNwT1J0bnvtv6YbmNSN9QSXb+1QSGyX6vK4q67Ow@mail.gmail.com>
Content-Language: en-US
From: Peter Eisentraut <peter@eisentraut.org>
In-Reply-To: <CAEZATCVLfMzNwT1J0bnvtv6YbmNSN9QSXb+1QSGyX6vK4q67Ow@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Archived-At: <https://www.postgresql.org/message-id/ef7c466d-e3b9-4d60-bc03-cd9b48581442%40eisentraut.org>
Precedence: bulk

On 04.09.24 12:33, Dean Rasheed wrote:
>> I left the 0001 patch alone for now and put the new rewriting
>> implementation into 0002.  (Unfortunately, the diff is kind of useless
>> for visual inspection.)  Let me know if this matches what you had in
>> mind, please.  Also, is this the right place in fireRIRrules()?
> Yes, that's what I had in mind except that it has to be called from
> the second loop in fireRIRrules(), after any RLS policies have been
> added, because it's possible for a RLS policy expression to refer to
> virtual generated columns. It's OK to do it in the same loop that
> expands RLS policies, because such policies can only refer to columns
> of the same relation, so once the RLS policies have been expanded for
> a given relation, nothing else should get added to the query that can
> refer to columns of that relation, at that query level, so at that
> point it should be safe to expand virtual generated columns.

If I move the code like that, then the postgres_fdw test fails.  So 
there is some additional interaction there that I need to study.