I have a situation Here.Several weeks Back,One of my application developer complained the performance issue in one of the application.I have looked at the statistics of the table,statistics on the table were stale and ran the statistics on that table,query's were running much faster.The same issue Happened in another application,and hoping that oracle will take the good decisions based on the statistics I ran the statistics for the tables involved in the query's but this time things got worse?Why is that??As per oracle documentation The optimizer has to have the up-to-date statistics on tables and on the indexes surrounding those tables,So how do we decide when to run the statistics on the tables making sure we don't worse the things.Thanks