Marcelo Arenas is an Associate Professor in the Department of Computer Science at the Pontificia Universidad Catolica de Chile. He received his PhD from the University of Toronto in 2005. His research interests are in different aspects of database theory, such as expressive power of query languages, database semantics, inconsistency handling, database design, XML databases, data exchange, metadata management and database aspects of the Semantic Web. He has received an IBM PhD Fellowship (2004), seven best paper awards (PODS 2003, PODS 2005, ISWC 2006, ICDT 2010, ESWC 2011, PODS 2011 and WWW 20...