Greg Rahn Explains Plans
Greg over at Structured Data has a fantastic piece titled “Troubleshooting Bad Execution Plans” which is a must-read for all. Learning about the GATHER_PLAN_STATISTICS hint alone was worth the price of admission.
Also time for me to re-evaluate the changes I made to OPTIMIZER_INDEX_CACHING and OPTIMIZER_INDEX_COST_ADJ a few versions back:
SQL> show parameters optimizer_index NAME TYPE VALUE ------------------------------------ ----------- ----- optimizer_index_caching integer 90 optimizer_index_cost_adj integer 10
