Sorry, Mike - can't give you much help with tuning an Oracle query. It sounds like your query is doing a tremendous amount of work. It might be worth reviewing the business requirements and figuring out whether a "divide and conquer" strategy would help. In many situations, I've found that the costs of building, storing, and maintaining tables of precomputed results can be lower than doing a bunch of aggregations or computations on the fly. You know best your business requirements and available resources, but don't be afraid to consider creative ways to solve problems!