Would it help that I have optimizer_dynamic_setting at 2 at the database level? I tried using a dynamic_sampling hint with a value of 4; that didn't make a difference on the cardinality estimate. On Tue, Nov 24, 2009 at 5:47 PM, Randolf Geist <info@xxxxxxxxxxxxxxxxxxxxx>wrote: > > So.... looking through this thread.... any way that dynamic sampling > > could be a bad boy here? > > > > Just a wild, off the cuff thought.... > > > > RF > > > > Robert G. Freeman > > Oracle ACE > > That is actually very good idea (all the time I had the impression I > missed something obvious) - in principle dynamic sampling should be able to > get the selectivity right. > > In this particular case the question would be if the overhead induced by > dynamic sampling would outweigh the benefit of it. It depends largely on the > sample level required to get helpful estimates - it might be worth a try to > add a "DYNAMIC_SAMPLING(LETTER_BIN 2)" hint - starting with a low sample > level (may be even 1). Higher sampling levels will get the selectivity right > but the overhead might be significant then. > > Regards, > Randolf > > Oracle related stuff blog: > http://oracle-randolf.blogspot.com/ > > Co-author of the forthcoming "OakTable Expert Oracle Practices" book: > http://www.apress.com/book/view/1430226684 > > http://www.amazon.com/Expert-Oracle-Practices-Database-Administration/dp/1430226684 > ______________________________________________________ > GRATIS für alle WEB.DE-Nutzer: Die maxdome Movie-FLAT! > Jetzt freischalten unter http://movieflat.web.de > >