"Richard Broersma" <richard.broersma@gmail.com> writes: > On Mon, Oct 13, 2008 at 9:52 AM, Reg Me Please <regmeplease@gmail.com> wrote: >> Is there a way to know how a NATURAL JOIN is actually done?
> Finally, NATURAL is a shorthand form of USING: it forms a USING list > consisting of exactly those column names that appear in both input > tables. As with USING, these columns appear only once in the output > table.
The OP's case is actually giving a cartesian product, because the tables don't have any column names in common.
You'd think this should be an error, but AFAICS the SQL spec requires it to behave that way.