Greg Stark <[EMAIL PROTECTED]> writes: > Tom Lane <[EMAIL PROTECTED]> writes: >> There is some stuff in the literature about how to make transformations >> of the last kind, but it requires additional executor smarts to do strange >> sorts of "generalized outer join" operations.
> Would these "generalized outer join" operations be general enough to handle IN > semantics? Or other subqueries? No, AFAICT it's just a weird way of defining a join operation. I did find some papers that talked about ways to push joins up and down past aggregations and GROUP BY, but that's a problem for another day. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org