The best systems that I have ever seen have two parts: (a) a read/write relational database (w/SQL) to persist data and (b) a read-only OLAP cube. With enough

The best systems that I have ever seen have two parts: (a) a read/write relational database (w/SQL) to persist data and (b) a read-only OLAP cube. With enough time, your powerusers will create the most insane reports imaginable using the OLAP cube view.