CSC News

April 02, 2013

Taming the Data Speaker Series Welcomes Dr. M. Tamer Özsu

Please join us on Friday, April 12th at 11:00 a.m. in room 3211 in Engineering Building 2 (EB2) for the Taming the Data invited-speaker series at NC State University.   Dr. M. Tamer Özsu, professor of Computer Science at the David R. Cheriton School of Computer Science of the University of Waterloo, is our special guest speaker.  The title of his talk is “gStore:  A Graph-based SPARQL Query Engine.”

Özsu’s research is in data management focusing on large-scale data distribution and management of non-traditional data. He is a Fellow of the Association for Computing Machinery (ACM), and of the Institute of Electrical and Electronics Engineers (IEEE), and member of Sigma Xi and American Association for the Advancement of Science (AAAS).
Abstract:  Resource Description Framework (RDF) has been proposed for modeling Web objects as part of developing the “semantic web”. It has also gained attention as a way to accomplish  web data integration. As the volume of RDF data has increased, interesting data management issues have arisen. In this talk I will discuss some of our recent work in this area, focusing on two results: answering SPARQL queries over RDF graphs, and processing aggregate SPARQL queries. The first problem focuses on evaluating SPARQL queries with wildcards over an RDF graph that sees frequent updates. We propose an approach that maps both the RDF data and the SPARQL query into graphs and converts the query evaluation problem to one of subgraph matching. In order to speed up query processing, we propose an indexing mechanism and pruning rules to reduce the search space. The second problem addresses the processing of aggregation queries over large RDF data sets. We propose a processing approach that partitions aggregate queries into smaller parts (called star queries), processes these efficiently, and joins the results of star queries to obtain more general results. We develop indexes to assist in executing star queries and to facilitate joining their results. This work is done within the context of the gStore project that is a joint project with Prof. Lei Zou of Peking University and Prof. Lei Chen of Hong Kong University of Science and Technology.
This invited-speaker series has been made possible thanks to generous support from Cisco, EMC, Premier healthcare alliance, SAS, the NC State Computer Science ePartners Program and the NC State Engineering Foundation.
The event is free and open to the public.  For more information about the talk, click here.
Directions to Centennial Campus and parking information can be found here.

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