I'm surprised that this worked

Hi,

I just wrote a query that I didn't expect to work but I
was pleasantly surprised that it did. It looked
something like this:

select
a.aaa,
c.ccc,
d.ddd1,
d.ddd2
from
tbla a,
tblb b,
tblc c,
funcd(c.id) d
where
a.something = something and
b.something = a.something and
c.something = b.something

How does it know which c.id to use for the function
without going all cartesian product on me? Maybe it
makes no sense for such a parameterised function to be
part of a cartesian product. Actually, that function
returns a setof record but only ever a single record.
That might be relevant.

I was sure I'd done something similar once that
(sensibly) didn't work, and I needed a loop to call the
function in, but I might be thinking of something in an
outer join's "on" clause. Does that make sense?

Even more impressed with Postgresql than usual. :-)

cheers,
raf