Re: Using non-grouping-keys at HAVING clause

On 9/8/23 09:42, Kohei KaiGai wrote:
> Hello,
> 
> I got a trouble report here:
> https://github.com/heterodb/pg-strom/issues/636
> 
> It says that PG-Strom raised an error when the HAVING clause used
> non-grouping-keys,
> even though the vanilla PostgreSQL successfully processed the query.
> 
> SELECT MAX(c0) FROM t0 GROUP BY t0.c1 HAVING t0.c0<MIN(t0.c0);
> 
> However, I'm not certain what is the right behavior here.
> The "c0" column does not appear in the GROUP BY clause, thus we cannot
> know its individual
> values after the group-by stage, right?

Wrong.  c1 is the primary key and so c0 is functionally dependent on it. 
  Grouping by the PK is equivalent to grouping by all of the columns in 
the table.
-- 
Vik Fearing