Deep > My query is using big hash joins. I had set PGA_AGGREGATE_TARGET=4GB. But > when I observed the pga statistics, I found that the max. pga used by a > session is 300M. That was the only user session running. > > Later I used manual PGA and defined the hash_area_size=2GB explicitly. > Then oracle started using the whole hash_area and the query ran faster. > > Would like to know why oracle did not allocated teh desired hash_area_size > when I used auto PGA? I guess you are in 9i. Are you? If yes give a look to ML note 147806.1. There are limitations... In 10g they have been relaxed and the memory manager is able to provide much more memory if necessary. HTH Chris -- //www.freelists.org/webpage/oracle-l