Change to hidden ORACLE parameter _b_tree_bitmap_plans
By Acshorten-Oracle on Mar 17, 2009
One of our customers noticed performance problems in Oracle 10g (and above) with Oracle Utilities Customer Care And Billing when the Oracle's Cost Based Optimizer chose bitmap index paths when there was no bitmap index.
If this problem exists with you then to remedy the problem the following SQL must be run and the database instance restarted:
ALTER SYSTEM SET "_b_tree_bitmap_plans"=false SCOPE=SPFILE;
If you want more information Refer to Metalink Bug Id: 8318459.