EFFICIENT MANAGEMENT OF MULTI-VERSION XML DOCUMENTS FOR E-GOVERNMENT APPLICATIONS

摘要

This paper describes our research activities in developing efficient systems for the management of multi-version XML documents in an e-Government scenario. The application aim is to enable citizens to access personalized versions of resources, like norm texts and information made available on the Web by public administrations. In the first system developed, four temporal dimensions (publication, validity, efficacy and transaction times) were used to represent the evolution of norms in time and their resulting versioning and a stratum approach was used for its implementation on top of a relational DBMS. Recently, the multi-version management system has migrated to a different architecture ("native" approach) based on a multi-version XML query processor developed on purpose. Moreover, a new semantic dimension has been added to the versioning mechanism, in order to represent applicability of norms to different classes of citizens according to their digital identity. Classification of citizens is based on the management of an ontology with the deployment of semantic Web techniques. Preliminary experiments showed an encouraging performance improvement with respect to the stratum approach and a good scalability behaviour. Current work includes a more accurate modeling of the citizen's ontology, which could also require a redesign of the document storage scheme, and the development of a complete infrastructure for the management of the citizen's digital identity.