Re: Key joins

Joel Jacobson <joel@compiler.org>

From: "Joel Jacobson" <joel@compiler.org>

To: "Laurenz Albe" <laurenz.albe@cybertec.at>, pgsql-hackers <pgsql-hackers@postgresql.org>

Cc: "Arne Roland" <arne.roland@malkut.net>, "Anders Granlund" <anders.granlund.0@gmail.com>, "Andreas Karlsson" <andreas@proxel.se>, "Vik Fearing" <vik@chouppes.com>

Date: 2026-05-31T14:40:06Z

Lists: pgsql-hackers

Attachments

v8-0001-Serialize-routine-definition-changes-with-depende.patch.gz (application/x-gzip)
v8-0002-Implement-FOR-KEY-join-support.patch.gz (application/x-gzip)
v8-0003-Add-information_schema.view_constraint_usage.patch.gz (application/x-gzip)

On Sun, May 31, 2026, at 10:05, Joel Jacobson wrote:
> On Fri, May 29, 2026, at 18:20, Laurenz Albe wrote:
>> On Fri, 2026-05-29 at 15:21 +0200, Joel Jacobson wrote:
>>> We actually originally considered TO and FROM as keywords for indicating
>>> direction, but FROM in a join clause causes confusion with the FROM
>>> clause itself.  Our user discussions over the last three years indicates
>>> that arrows are clearer and less ambiguous.
>>> 
>>> It's also worth to mention that SQL/PGQ also uses ASCII arrows to
>>> indicate direction for its graph pattern syntax.
>>
>> I understand the problem with FROM, and I have no objection to the
>> arrows.
>
> Thanks for reviewing.
>
> v7 updates 0002 to match the revised Change Proposal wording for
> GROUPING SETS/ROLLUP/CUBE:

v8 fixes another nondeterministic isolation-test ordering issue seen by
cfbot on the FreeBSD machine.

0001 and 0003 are unchanged from v7.

/Joel