Journal of Digital Information Management Zouhaier Brahmia, Fabio Grandi, Rafik Bouaziz 14 5 2016 http://dline.info/fpaper/jdim/v14i5/jdimv14i5_1.pdf Although a lot of research work has been done concerning schema changes that deal with basic components of XML Schemas, like element and attribute declarations, simple types, and complex type definitions, the current literature of the XML database field does not include any paper that studies changes of advanced concepts of XML Schemas, like XML namespaces, local (or global) qualified (or unqualified) declarations, and schema definition styles (e.g., Russian Doll, Garden of Eden). In this paper, we study how XML namespace evolution is handled in an XML environment that supports both schema and document versioning. To the best of our knowledge, this is the first work on such a topic. Indeed, we propose a systematic approach that allows specifying changes on XML namespaces defined in XML Schemas, and propagating their effects to underlying XML documents, while maintaining all XML schema and XML instance versions.