On Sun, 15 May 2011 07:39:06 +0900,
Ian Lawrence Barwick <barwick(at)gmail(dot)com> wrote:
[...]
> Your query doesn't have an explicit join and is producing a cartesian
> result.
> I don't think a self- join will work here; a subquery should produce
> the result you're after:
> SELECT * FROM tmp t1 WHERE NOT EXISTS(SELECT TRUE FROM tmp t2 WHERE
> t2.b=t1.a);
This produces exactly the result I'm after. I'll need to understand the
EXISTS statement there in more detail.
Thanks!
--
Seb