Re: [GENERAL] postgresql how to duplicate rows in result.

On Thu, Feb 16, 2017 at 10:27 AM, David G. Johnston
<david.g.johnston@gmail.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