Horton

Re: pg18: Virtual generated columns are not (yet) safe when superuser selects from them

Matthias van de Meent <boekewurm+postgres@gmail.com>

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From: Matthias van de Meent <boekewurm+postgres@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Matthias van de Meent <boekewurm+postgres@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Feike Steenbergen <feikesteenbergen@gmail.com>, jian he <jian.universality@gmail.com>, "David G. Johnston" <david.g.johnston@gmail.com>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2025-05-29T19:04:15Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Restrict virtual columns to use built-in functions and types

  2. Fix virtual generated column type checking for ALTER TABLE

  3. Expand virtual generated columns in the planner

On Thu, 29 May 2025 at 20:30, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Matthias van de Meent <boekewurm+postgres@gmail.com> writes:
> > On Thu, 29 May 2025 at 15:44, Robert Haas <robertmhaas@gmail.com> wrote:
> >> But so far - apart from this feature - we
> >> have managed to avoid making it categorically unsafe for the superuser
> >> to run "SELECT * FROM table"
>
> > With CREATE RULE [0], a table owner can redefine what happens during
> > e.g. SELECT * FROM table.
>
> That's a view, not a table.

Ah, it's hidden deeper into the docs than I'd first read, but indeed
ON SELECT is only allowed for views. The syntax itself nor the 'event'
description in the parameters detail this restriction, which is where
I looked.

Sorry for the noise, and thank you for correcting me.

Kind regards,

Matthias van de Meent
Neon (https://neon.tech)