%0 Conference Paper %B Proceedings of the National Conference on Artificial Intelligence %D 2007 %T GRIN: A graph based RDF index %A Udrea,O. %A Pugliese, A. %A V.S. Subrahmanian %X RDF (“Resource Description Framework”) is now a widelyused World Wide Web Consortium standard. However, methods to index large volumes of RDF data are still in their infancy. In this paper, we focus on providing a very lightweight indexing mechanism for certain kinds of RDF queries, namely graph-based queries where there is a need to traverse edges in the graph determined by an RDF database. Our approach uses the idea of drawing circles around selected “center” vertices in the graph where the circle would encom- pass those vertices in the graph that are within a given dis- tance of the “center” vertex. We come up with methods of finding such “center” vertices and identifying the radius of the circles and then leverage this to build an index called GRIN. We compare GRIN with three existing RDF indexex: Jena, Sesame, and RDFBroker. We compared (i) the time to an- swer graph based queries, (ii) memory needed to store the index, and (iii) the time to build the index. GRIN outper- forms Jena, Sesame and RDFBroker on all three measures for graph based queries (for other types of queries, it may be worth building one of these other indexes and using it), at the expense of using a larger amount of memory when answering queries. %B Proceedings of the National Conference on Artificial Intelligence %V 22 %P 1465 - 1465 %8 2007/// %G eng