On Thu, Dec 15, 2005 at 09:25:42AM -0500, Tom Lane wrote: > 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.
Might be worth adding a TODO for that and including links to the papers. There's enough people that seem to drop in with PhD thesis and what-not pulled from the TODO that someone could end up doing this work for us. -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
