Feedback-ID: i675e48f3:Fastmail
MIME-Version: 1.0
Date: Thu, 19 Feb 2026 17:31:12 -0500
From: "Greg Burd" <greg@burd.me>
To: "Andres Freund" <andres@anarazel.de>
Cc: "Jeff Davis" <pgsql@j-davis.com>,
 pgsql-hackers <pgsql-hackers@postgresql.org>
Message-Id: <b8e07500-587d-4360-8f9e-89b14d1c0edc@app.fastmail.com>
In-Reply-To: 
 <akciabcu3b2hchj7adxhu4kovfaozp2pcn2z7sdljfthxcyg4o@7e6sfyzipvyy>
References: <5165C147-B476-4E3D-AAA9-11C0B966FC4D@greg.burd.me>
 <9394564A-5764-4DCA-8845-8AE102DE61DC@greg.burd.me>
 <97769442-2ed7-4fe0-a393-7e2b5ff7ff58@app.fastmail.com>
 <a9c8ee0d-bb60-418b-847f-49c4332a09c4@app.fastmail.com>
 <3e1b9075c92808a7356e79087ba51910e5db5a30.camel@j-davis.com>
 <da3400d5-e5e0-4d24-bd49-822c72c9894f@app.fastmail.com>
 <fc17cbe85c24ff9d3cf43bfb37e6ca0d483fb2b4.camel@j-davis.com>
 <e1d06b18-2ebb-466e-bc0f-5d426d17a32e@app.fastmail.com>
 <akciabcu3b2hchj7adxhu4kovfaozp2pcn2z7sdljfthxcyg4o@7e6sfyzipvyy>
Subject: Re: Expanding HOT updates for expression and partial indexes
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
Archived-At: <https://www.postgresql.org/message-id/b8e07500-587d-4360-8f9e-89b14d1c0edc%40app.fastmail.com>
Precedence: bulk


On Thu, Feb 19, 2026, at 3:43 PM, Andres Freund wrote:
> Hi,
>
> On 2026-02-17 16:15:02 -0500, Greg Burd wrote:
>> > Why does simple_heap_update() need to do the HeapDetermineColumnsInfo()
>> > inside heap_update()? It seems like you're trying to avoid doing the
>> > same work the executor is doing to determine the modified_attrs bitmap,
>> > but either (a) the work is cheap; or (b) the work to make the bitmap is
>> > expensive.
>> 
>> simple_heap_update() is exclusively called during catalog tuple updates and
>> does not involve the executor at all, these are direct calls into heap to
>> store catalog tuples.

Hey Andres,

> Just FYI, there are probably a fair number of extensions using
> simple_heap_update().  That number used to be a lot higher, but I don't think
> there should be a hard assumption about it just being used for catalog updates
> in the code.

Makes sense.  These patches don't change simple_heap_update() in any functional way and so extensions should be fine.

> Greetings,
>
> Andres Freund

best.

-greg