Hi Brandon,
thank you for the hint
ML Note:272202.1 discussed Bug bug 4570598, related to FIRST_ROWS hint/optimizer mode.
FIRST_ROWS is as far as know some kind of "hybrid" between RBO und CBO -> many heuristic rules are used, and that is why the cost calculations in this mode are not always driving the decisions of CBO.
Anyway, I have tried with
"_sort_elimination_cost_ratio" 1, 10, 50, even 100, but I am getting the same (suboptimal) plan.
Best Regards, Milen
P.S. I further problem is that I can not use "_sort_elimination_cost_ratio" as hint (Oracle version is 9i, not 10G)
--
"Ein Herz für Kinder" - Ihre Spende hilft! Aktion: www.deutschlandsegelt.de
Unser Dankeschön: Ihr Name auf dem Segel der 1. deutschen America's Cup-Yacht!
--
http://www.freelists.org/webpage/oracle-l
Received on Mon Dec 18 2006 - 05:44:35 CST
