The data warehouse is the cornerstone for the production of business knowledge in the organization. The foundation of the quality of the business knowledge is the quality of the data in the data warehouse. Determination of dimensions of data quality in the data warehouse has been obtained through the intuitive, the empirical and the ontological approaches. The first point of this working paper is that data quality is not a static measure and that awareness of the data quality dimensions is a prerequisite to improve the data quality. The second point is that selection is the cornerstone of data quality in the data warehouse in relation to the quality dimensions. Thirdly, that post-load improvement of the data quality is obtainable. Metadata can be added incrementally containing information on the use of data – including the users' selections within the data warehouse.