http://www.dataversity.net/careful-derived-data/
"In contrast, careless use of derived data can ruin a day-to-day operational application. End users concurrently read and write to the database from various interfaces. In addition, applications have ongoing maintenance and revisions that disrupt the code base. In these situations, derived data is just asking for trouble. Often the desired performance boost is illusory while the quality detriment is severe."
blog-post-be-careful-with-derived-data#view-for-derived-data1 2"Sometimes it's helpful to wrap a view around a table. The view definition can include derived data calculations. Then applications and interfaces can access views for a consistent implementation of derived data." blog-post-be-careful-with-derived-data#view-for-derived-data1 2