Wolfgang >Autotrace uses explain and that can produce a different plan from the >Christian referred to the indes tie-break rule as well in his first >reply. If there are two suitable indexes, the RBO chooses the one with >the higher object_id (i.e. the newer one) - or is it the other way >around? The newer is used. Regards, Chris -- http://www.freelists.org/webpage/oracle-l