Nowadays database systems (DBSs) are state-of-the art for managing complex data in information systems. Unfortunately, DBSs are not aware of the context of their usage. Query results are retrieved without considering the context of the user/device issuing the query. In many cases, this feature is added by a context managing middle-ware. This paper outlines a scenario for context aware mobile services. In the paper we introduce an XML-based XREAL model for formalizing contextual information and queries highlighted in the scenario and discuss how XREAL can be implemented in a modern database system. By utilizing XREAL, it is possible to realize context aware mobile information systems based on the available DBSs without additional middle-wares.