speed up exadata

http://www.bobbydurrettdba.com/2013/04/05/lessons-from-preparing-my-exadata-talk/



1. Exadata Smart Scans bypass the block buffer cache
2. Exadata Smart Scans happen instead of FULL scans
3. Make indexes invisible or increase optimizer_index_cost_adj to encourage FULL scans
4. Exadata Smart Scans tend to be part of a HASH JOIN
5. HASH JOINs can be sped up by adding PGA memory – pga_aggregate_target
6. You can free memory by reducing the size of the block buffer cache – sga_max_size