Turn on Oracle Database Hints
When set to true, this option enables Oracle hints that may significantly improve performance when querying for inbox results, assuming that the user inbox queues are not very large (for example, less than 1,000 tasks per role or user). For large queues this will not provide benefits and may possibly slow performance. This option is set to false (off) by default:
-Dtask.use.oracle.hint=true|false