How Long does Overnight Database Processing take?
It is not safe to assume that you will have more than 10 hours overnight to achieve all the processing, even if the user day is only 8 or 9 hours long. Delays in data arrival can cause a company significant problems, and one must make sure that he/she will be able to complete the overnight processing without running over into the business day. Naturally this will vary from data warehouse to data warehouse, but of the 10 hours allowed to complete the overnight processing, it is normal to have about 60% available to complete the post processing of the data and the aggregation and index creation. That gives about 6 hours to complete all these tasks.