Building a secure star schema in data warehouses by an extension of the relational package from CWM

Data Warehouses (DWs) are widely accepted as the core of current decision support systems. Therefore, it is vital to incorporate security requirements from the early stages of the DWs projects and enforce them in the further design phases. Very few approaches specify security and audit measures in the conceptual modeling of DWs. Furthermore, these security measures are specified in the final implementation on top of commercial systems as there is not a standard relational representation of security measures for DWs (i.e. the well-known star schema does not allow us to specify security and audit measures on its multidimensional representation of data; instead, they must be specified on top of the implemented relational tables). On the other hand, the Common Warehouse Metamodel (CWM) has been accepted as the standard for the exchange and the interoperability of metadata. Nevertheless, it does not allow us to specify security measures for DWs. In this paper, we make use of the own extension mechanisms provided by the CWM to extend the relational package in order to build a star schema that represents the security and audit rules captured during the conceptual modeling phase of DWs. Finally, in order to show the benefits of our extension, we apply it to a case study related to the management of the pharmacy consortium business.