Re: First draft of PG 19 release notes - Mailing list pgsql-hackers

On Fri, May  1, 2026 at 10:16:24AM +0900, Richard Guo wrote:
> On Wed, Apr 15, 2026 at 10:19 AM Bruce Momjian <bruce@momjian.us> wrote:
> > I have completed the first draft of the PG 19 release notes:
> >
> >         https://www.postgresql.org/docs/devel/release-19.html
> 
> I just committed 8d829f5a0 to fix JSON_ARRAY(subquery) to return an
> empty JSON array instead of NULL over an empty result set, per the
> SQL/JSON standard.  Since this is a user-visible behavior change, we
> need to add an item to the v19 migration section to call it out.
> 
> Suggested entry:
> 
>  - Make JSON_ARRAY(query_expression) return an empty JSON array when
>    the subquery returns no rows (Richard Guo)
> 
>    Previously, an empty result set produced NULL.  This corrects the
>    behavior to match the SQL/JSON standard.  Application code that
>    relied on the previous NULL behavior may need to be updated.

I will add this as soon as I update with the new commits.  Thanks.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Do not let urgent matters crowd out time for investment in the future.