Feedback-ID: ie0a040ee:Fastmail
Message-ID: <84f20d0d-3bc8-4843-bd7e-21bce20f8582@eisentraut.org>
Date: Wed, 24 Jun 2026 10:52:24 +0200
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH] Fix null pointer dereference in PG19
To: Paul A Jungwirth <pj@illuminatedcomputing.com>,
 jian he <jian.universality@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>,
 Aleksander Alekseev <aleksander@tigerdata.com>,
 PostgreSQL Development <pgsql-hackers@postgresql.org>
References: 
 <CAJ7c6TME+ix6VRf-2TPnVTsj8qn_hy6sYAOmMhZEivwsu2wS6g@mail.gmail.com>
 <626986.1776785090@sss.pgh.pa.us>
 <CACJufxFgKVL=NnPocAwhRFqpLHckN3N1Ndf7FjGNTdtsAA26mg@mail.gmail.com>
 <CA+renyW52FJ=+pnh+N_xqjUev_MNUCk_mgD2UC7UT0jyAHCE8Q@mail.gmail.com>
From: Peter Eisentraut <peter@eisentraut.org>
Content-Language: en-US
In-Reply-To: 
 <CA+renyW52FJ=+pnh+N_xqjUev_MNUCk_mgD2UC7UT0jyAHCE8Q@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Archived-At: 
 <https://www.postgresql.org/message-id/84f20d0d-3bc8-4843-bd7e-21bce20f8582%40eisentraut.org>
Precedence: bulk

On 15.05.26 23:21, Paul A Jungwirth wrote:
> On Thu, Apr 23, 2026 at 9:45 PM jian he <jian.universality@gmail.com> wrote:
>>
>> On Tue, Apr 21, 2026 at 11:24 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>>
>>> * I'd tend to move the anti-FDW check to execution too.
>>> It's not actively wrong, since nowadays we don't permit
>>> relations to change relkind, but it seems out of place.
>>> Also, it seems inadequate to deal with the case of a target
>>> that is a partitioned table having FDW partitions.
>>>
>> Hi.
>>
>> Instead of adding another subnode in CheckValidResultRel,
>> I am passing ModifyTable to it, this will be more future-proof.
> 
> Thank you for working on this! I started a new thread at [1] so that I
> could give it a commitfest entry.
> 
> Your patch looks great to me. I didn't notice that you had posted one,
> so I made my own, but yours is better. Doing the check in
> CheckValidResultRel makes a lot of sense.
> 
> I thought there was one other case we should test for: when a
> partition has a child FDW that gets pruned, we should not raise an
> error. So I swapped in my own tests, which were otherwise similar to
> yours.
> 
> That new thread also includes a patch to move the functionality check
> into plan-time.
> 
> [1] https://www.postgresql.org/message-id/CA%2BrenyUte0_UJsJiDJQi82oaBsMJn%3Dcct0Wn%3DvOqXtuDn%3DYYJA%40mail.gmail.com

I don't understand the status of this discussion.  The original bug 
report is related to views and INSTEAD OF triggers.  But the last few 
patches that have been posted here appear to be unrelated to that 
specific issue.