------------------------------------------------------------------ Speaker: Dr. Renee J. Miller Department of Computer Science University of Toronto Topic: "Clio: Creating and Managing Schema Mappings" Date: Monday, 19 August 2002 Time: 10:00am - 11:00am Venue: Room 2306 Phase I (via lift nos. 17/18) HKUST Abstract: We present a novel framework for mapping between any combination of XML and relational schemas, in which a high-level, user mapping is translated into semantically meaningful queries that transform source data into the target representation. Our approach works in two phases. In the first phase, the high-level mapping, expressed as a set of inter-schema correspondences, is converted into a set of mappings that capture the design choices made in the source and target schemas (including their hierarchical organization as well as their nested referential constraints). The second phase translates these mappings into queries over the source schemas that produce data satisfying the constraints and structure of the target schema, and preserving the semantic relationships of the source. Non-null target values may need to be invented in this process. The mapping algorithm is complete in that it produces all mappings that are consistent with the schema constraints. We have implemented the translation algorithm in Clio, a schema mapping tool, and present our experiences on several real schemas. The mappings produced by Clio can be used both within data integration where source data is queried through a virtual target schema and in peer-to-peer systems where data is exchanged between peers. We discuss the often subtle difference between the semantics of data integration and that of peer-to-peer data exchange. This is joint work with Ron Fagin, Mauricio Hernandez, Phokion Kolaitis, Lucian Popa, and Yannis Velegrakis. ****************** Biography: Rene J. Miller is an associate professor of computer science at the University of Toronto. She received the 1997 Presidential Early Career Award for Scientists and Engineers (PECASE), the highest honor bestowed by the United States government on outstanding scientists and engineers beginning their careers. She is a recipient of the NSF CAREER Award, the Premier's Research Excellence Award, and an IBM Faculty Award. Her research interests are in the efficient, effective use of large volumes of complex, heterogeneous data. This interest spans heterogeneous databases, data mining, and data warehousing. She received her PhD in Computer Science from the University of Wisconsin, Madison and bachelor's degrees in Mathematics and Cognitive Science from MIT. For enquiry, please call 2358 7008 ** All are Welcome ** ----------------------------------------------------------------------