Thanks you for sharing your experience Leo. It's a good and useful article. We use a data warehouse where the data from stage is loaded alternately into 2 sets of identical star schema (the difference is just the suffix at the end of table names) and there are a set of views which select from those sets. The downtime is minimal, just to drop and recreate the views to point to the just loaded set of tables. We have been using this for 6 years. Regards, Vincent