Re: GROUP BY using tablename.* does not work if tablename has 1 column with NULL values

Narayanan:

On Mon, 11 Oct 2021 at 14:10, Narayanan Iyer <nars@yottadb.com> wrote:
...
> You are right. My inner query was an outer join returning 3 rows. But what I did not understand was that the NULLs in
2of the 3 rows were different because 1 was a composite NULL and 1 was a ROW(NULL) and hence they showed up as 2
differentNULLs/rows even after a GROUP BY. Tom's explanation cleared it up for me. 

Perfect. null rows, row(null) and siblings are extremely tricky, I
always try to avoid them, just pointed it in case you did not run the
subquery first and counted results.

Francisco Olarte.