1. The global and partition statistics updated right after data loading. The volumn is only 30% more, but the response time is like 10 times slower.
2. How often should the index get analyzed? Indexes are all created with COMPUTE STATISTICS. How big is the impact on the database performance if analyzing at day time? (using dbms_stats package).
3. The big fact table is range-hash partitioned. Oracle so far does not support table compression on a composite partitioned table, does it? Have you ever done a table compression on a composite partitioned table? How much it would improve the performance? What's the disadvantange if just compress the partitions without update?

Thanks!