Re: postgresql how to duplicate rows in result.

On Thu, Feb 16, 2017 at 10:27 AM, David G. Johnston
<david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
> If it wasn't lateral the reference to number in "generate_series(1, number)"
> would fail.

huh -- I didn't know that! Testing it out, all JOIN types imply
LATERAL if the function call is tlist SRF style (which is pretty werid
IMO) I tend to avoid optional words (with the important exception of
AS for column list renames) but I think it's a good idea to disclose
LATERAL in this case. It's a big clue to the reader what is going on
and the expanded form:

SELECT foo.* FROM foo CROSS JOIN LATERAL (SELECT a,b FROM func(foo.bar)) q;

... requires LATERAL to be explicitly stated. This form is more
general since it can be cleanly used when func() returns more than one
column.

merlin