Accommodating Changes in Semistructured Databases Using Multidimensional OEM

Multidimensional Semistructured Data (MSSD) are semistructured data that present di erent facets under di erent contexts. Contexts represent alternative worlds, and are expressed by assigning values to a set of user-de ned variables called dimensions. The notion of context has been incorporated in OEM, and the extended model is called Multidimensional OEM (MOEM), a graph model for MSSD. In this paper, we explain in detail how MOEM can represent the history of an OEM database. We discuss how MOEM properties are applied in the case of representing OEM histories, and show that temporal OEM snapshots can be obtained from MOEM. We present a system that implements the proposed ideas, and we use an example scenario to demonstrate how an underlying MOEM database accommodates changes in an OEM database. Furthermore, we show that MOEM is capable to model changes occurring not only in OEM databases, but in Multidimensional OEM databases as well.