Abstract:

Trajectory data warehouses, which gather data about mobile objects activities, may be autonomous and consequently may change frequently their structures and contents. This kind of change can alter the trajectory data warehouse associated schema, the analysis process and thus the decision making requirements on which the initial conceptual model is performed. For this reason, a TDW maintenance technique is needed to adapt the defined schema. In this paper, we will focus on maintaining a trajectory data warehouse after schema changes using for this a versioning approach allowing the existence of many versions of a same trajectory data warehouse. However, querying such data warehouse versions is considered as a big challenge since data returned by queries may vary according to queried versions. Hence, a solution to ensure data mapping between different versions is required in order to give valid results necessary for providing elements leading to efficient decisions.