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

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>

To: Feike Steenbergen <feikesteenbergen@gmail.com>

Cc: Robert Haas <robertmhaas@gmail.com>, jian he <jian.universality@gmail.com>, "David G. Johnston" <david.g.johnston@gmail.com>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>

Date: 2025-05-29T18:15:22Z

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 →

Restrict virtual columns to use built-in functions and types
- 0cd69b3d7ef3 18.0 landed
Fix virtual generated column type checking for ALTER TABLE
- 49fe1c83ecf3 18.0 landed
Expand virtual generated columns in the planner
- 1e4351af329f 18.0 cited

Feike Steenbergen <feikesteenbergen@gmail.com> writes:
> pg_restore may have issues though, as it will run these functions
> for GENERATED STORED columns?

pg_restore is already fairly exposed, as it will run tables' CHECK
constraints, index expressions, etc.  I don't think GENERATED STORED
makes that picture much worse.

As Robert said upthread, it would be nice to make all this more
secure.  But it'd presumably involve user-visible semantics changes
along with the performance worries I mentioned.  It's a dauntingly
large task...

			regards, tom lane