System Ⅱ:A Native RDF Repository Based on the Hypergraph Representation for RDF Data Model
In order to manage the increasing amount of RDF data, an RDF repository should provide not only necessary scalability and efficiency, but also sufficient inference capabilities. Though existing RDF repositories have made progress towards this goal, there is still ample space for improving the overall performance. In this paper, we propose a native RDF repository, System Ⅱ, to pursue a better tradeoff among the system scalability, the query efficiency, and the inference capabilities. System Ⅱ takes the hypergraph representation for RDF as the data model for its persistent storage, which effectively avoids the costs of data model transformation when accessing RDF data. Based on this native storage scheme, a set of efficient semantic query processing techniques are designed. First, several indices are built to accelerate RDF data access including a value index, a labeling scheme for transitive closure computation, and three triple indices. Second, we propose a hybrid inference strategy under the pD* semantics to support inference for OWL-Lite with a relatively low computational complexity. Finally, we extend the SPARQL algebra to explicitly express inference semantics in logical query plan by defining new algebra operators. The results of performance evaluation on the LUBM benchmark show that System Ⅱ has a better combined metric value than the other comparable systems.
Gang Wu Juanzi Li Jianqiang Hu Kehong Wang
Computer Science and Technology,Tsinghua University Beijing,P.R.China
国际会议
The Ninth International Conference on Web-Age Information Management(第九届web时代信息管理国际会议)(WAIM 2008)
张家界
英文
2008-07-20（万方平台首次上网日期，不代表论文的发表时间）