WITH RECURSIVE, demonstrated as a solution to NOCOUG's sql challenge: http://hype-free.blogspot.com/2009/04/nocoug-sql-challenge.html Instance Caging is interesting. The documentation explains two different approaches for managing cpu allocations, over-provisioning and partitioning, but it isn't clear how to implement those approaches. Will Oracle change cpu licensing requirements if you limit all instances to N cpus? Unlikely, I suppose. DBMS_PARALLEL_EXECUTE should eliminate the need for DIY parallelism. The scheduler's new features for file watching events and email notification should be helpful.