Most data warehouse performance problems are rooted in a poor data model. A dimensional model is the best choice for a data warehouse. Just as there are steps you can take to ensure the success of your data warehouse project, there are many pitfalls you can avoid in order to prevail. Wrong Architecture - Data warehouses are often built several times before the correct architecture is utilized. Do your research and determine what architecture fits your business needs best.
Clean data is essential to a successful data warehouse.
Without it, business decisions cannot be made in confidence because the data does not accurately represent the information required to make those decisions. These are also often called independent data marts, and they are not integrated with central metadata. There are no common business rules, semantics, and definitions. If you fail to provide a system that will support any business unit, you will be forced either to implement additional warehouses or to start again. A bottom-up approach is highly advised for a successful implementation.