Re: pg18 bug? SELECT query doesn't work

Eric Ridge <eebbrr@gmail.com>

From: Eric Ridge <eebbrr@gmail.com>
To: pgsql-general <pgsql-general@postgresql.org>
Date: 2026-01-06T15:52:56Z
Lists: pgsql-hackers, pgsql-general
> On Jan 6, 2026, at 10:22 AM, Eric Ridge <eebbrr@gmail.com> wrote:
> 
> Here's a reduced test case:

Here's an even more reduced test case.  No tables or data:

# SELECT * FROM (SELECT upper(unnest(ARRAY['cat', 'dog'])) as animal FROM generate_series(1, 10) GROUP BY 1) x WHERE animal ilike 'c%';

pg15 returns:

 animal  
--------
 CAT
(1 row)

and pg18 says:

# SELECT * FROM (SELECT upper(unnest(ARRAY['cat', 'dog'])) as animal FROM generate_series(1, 10) GROUP BY 1) x WHERE animal ilike 'c%';
ERROR:  set-valued function called in context that cannot accept a set
LINE 1: SELECT * FROM (SELECT upper(unnest(ARRAY['cat', 'dog'])) as ...
                                    ^

Thanks!

eric




Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Fix unsafe pushdown of quals referencing grouping Vars

  2. Introduce an RTE for the grouping step