Re: Direct Toast PoC

Hi Hannu!

Haven't looked at the code yet but want to mention - I've tried 'direct'
approach some time ago [1]
using list-like representation. Despite giving speedup for relatively small
values and does not having
TOAST index table at all, the performance degraded over standard TOAST with
large ones,
and dependency on TIDs have the immediate effect of VACUUM FULL breaking
the overall structure,
so it should be modified accordingly too.
Michael had already answered that, you could check out [1] for discussion.

[1]
https://www.postgresql.org/message-id/CAN-LCVOh9DRWNqoDUx+Q1ZDM_O3VyX6ctRuEX0mzA+_JTkUKvg@mail.gmail.com

On Thu, Jul 30, 2026 at 7:41 AM Michael Paquier <michael(at)paquier(dot)xyz> wrote:

> On Wed, Jul 29, 2026 at 09:13:47PM +0200, Hannu Krosing wrote:
> > I would like to propose a design and prototype implementation for a new
> > TOAST format, which we are calling **Direct TOAST**.
> > Not a big change, just leaving out the index part.
> > Hopefully this gives TOAST another 25-30 years :)
>
> I am going to be honest here, but I think beginning a thread this way
> is sloppy. First, the entire email and its contents are entirely
> AI-generated, perhaps you have spent some time double-checking the
> contents of the message but it does not give this impression at all;
> at least you are being honest regarding the code by saying that you
> have *not looked at the code at all*. And even if the code is
> generated, looking at the result is the first thing you should try to
> do, especially if you are asking people to look at it.
>
> Relying on such tools is a trend these days, and that's fine because
> LLM models are tools and they can be terribly efficient when used
> well, but it does not change the review and lookup part (Postgres
> committers do that). Some people seem to have success with such
> tools, which is also fine. But please, if you plan to ask people to
> spend some time on what you are doing, the least you can do is to give
> the impression that you have yourself spent some time on the actual
> code. I cannot speak for others, but beginning a thread this way
> discourages me entirely to look at what you have sent.
>
> Okay, spoiler: I did look at the code, and your LLM has just been
> hard-coding a new vartag_external, plumbing it into the TOAST
> internals without caring about any concept of backward-compatibility.
> Posting patches based on HEAD and not a stable branch would be a
> better idea, as well, as a starter. I understand that this is a POC,
> still.
>
> Please do not take it bad, this is just my opinion. I think that
> time is the most important resource we have. It is limited. However,
> beginning a thread this way does not give the impression that you
> value the time of other people at all.
>
> My 2c.
> --
> Michael
>

--
Regards,
Nikita Malakhov
Postgres Professional
The Russian Postgres Company
https://postgrespro.ru/