I have a problem regarding elapsed time and explain plan.
When I’m trying to tune my select statement with the SQL Optimizer i get an explain plan with the cost of 560 and an elapsed time of more than 1:30 h. After that i executed the same statement in Toad and it took only 6 sec! So I executed the statement again in the SQL Optimizer to be sure that its not because of the cache. It took again more than an hour. So I investigated the session browser while running the query with the SQL Optimizer to see the actual explain plan of it and there it showed an completely different explain plan with costs of over 88000!!!
Maybe also helpful information: many of the produced alternatives also need only some seconds to be executed.