Distributed Semantic Query Based On Sparql

In presence of web, one critical challenge is how to globally publish, seamlessly integrate and transparently locate geographically distributed database resources with such "open" settings. Web-scale database integration has been one of the main driving forces for both Semantic Web research and Grid development.DartGridV3 proposes a semantic-based approach and provides a set of tools and middleware to support the global sharing of database resources using Grid as platform and dynamically integrates information from autonomous local databases managed by heterogeneous database management systems in dynamic, open and multi-institutional environment.For a query involving more than one database, global query optimization should be performed to achieve good overall system performance. Because there are some fundamental differences between traditional distributed Database Management System (DBMS) and Database Gird System (DBGS) which stems from autonomy and heterogeneity of the database nodes participating in DBGS, query optimization techniques in distributed DBMS can not trivially and directly be applied to DBGS.Since DBGS supports the database nodes dynamically participate in or quit the system and sets target for facing more "open" settings of Web environment, the query processing problem is much more difficult in database Grid environment than in centralized, distributed, and multi- database. But it is very important for the success of system. SPAROL-based algorithm for query optimization in semantic database Grid is proposed by extending the best known semijoin technique. The design and implementation of some SPARQL syntax that are newly introduced for DartGridV3 also have been discussed in detail.The original motivation of designing and developing DartGridV3 is to provide aplatform for Tradition Chinese Medicine (TCM) Grid that supports TCM language knowledge storage, concept-based information retrieval and information integration. We developed the full text search engine for semantic database Grid and normal users can enter the system by the Web site of DartSearch. The system has been successfully deployed at China Academy of Traditional Chinese Medicine and currently provides access to over 70 databases including TCM herbal medicine databases, TCM compound formula databases, clinical symptom databases, traditional Chinese drug databases, traditional Tibetan drug databases, and so on.