all, recently i have a dev machine 10g on itanium ia-64 another linux is itanium ia-64 with 9i the performance on 10g (10.2.0.3) is dropped for almost 1/3 from the 9i, if someone has the same experiences, pls share.... all these parameters doesn't help either... alter system set optimizer_features_enable='9.2.0' scope=both; alter system set "_optimizer_cost_based_transformation" =on scope=both; alter system set "_gby_hash_aggregation_enabled" = TRUE scope=both; -- regards ujang -- //www.freelists.org/webpage/oracle-l