Generating Relations from XML Documents
This paper discusses several mechanisms for creating relations out of XML documents. A relation generator consists of two parts: (1) a tuple of path expressions and (2) an index indicating which path expressions may not be assigned the null value. Evaluating a relation generator involves finding tuples of nodes that satisfy the path expressions and are related to one another in a meaningful fashion. Different semantics for evaluation are given that take into account the possible presence of incomplete information. The complexity of generating relations from documents is analyzed and evaluation algorithms are described.
Unable to display preview. Download preview PDF.
- U. Chakravarthy and J. Minker. Multiple query processing in deductive databases using query graphs. In Proceedings of International Conference on Very Large Data Bases, pages 384–391. Morgan Kaufmann, 1986.Google Scholar
- S. Cohen, Y. Kanza, and Y. Sagiv. SQL4X: A flexible query language for XML and relational databases. In Proc. of the 8th International Workshop on Database and Programming Languages (DBPL), pages 263–280, Marino, (Rome, Italy), September 2001. Springer-Verlag.Google Scholar
- S. Cohen, Y. Kanza, and Y. Sagiv. Select project queries over xml documents. In Proc. 5th Workshop on Next Generation Information Technologies and Systems, pages 2–13, Caesarea (Israel), June 2002. Springer-Verlag.Google Scholar
- M. Garofalakis, A. Gionis, R. Rastogi, S. Seshadri, and K. Shim. XTRACT: A system for extracting document type descriptors from xml documents. In Proc. 2000 ACM SIGMOD International Conference on Management of Data, pages 165–176, Dallas (Texas, USA), May 2000. ACM Press.Google Scholar
- M. Graham. On the universal relation. Technical report, University of Toronto, Toronto (Canada), 1979.Google Scholar
- A. Gupta, V. Harinarayan, and A. Rajaraman. Virtual database technology. In Proc. 14th International Conference on Data Engineering, pages 297–301, Orlando (Florida, USA), Feb. 1998. IEEE Computer Society.Google Scholar
- Y. Kanza and S. Sagiv. Flexible queries over semistructured data. In Proc. 20th Symposium on Principles of Database Systems, pages 40–51, Santa Barbara (California, USA), May 2001. ACM Press.Google Scholar
- S. Nestorov, S. Abiteboul, and R. Motwani. Extracting schema from semistructured data. In Proc. 1998 ACM SIGMOD International Conference on Management of Data, pages 295–306, Seattle (Washington, USA), June 1998. ACM Press.Google Scholar
- A. Rajaraman and J. D. Ullmann. Querying websites using compact skeletons. In Proc. 20th Symposium on Principles of Database Systems, pages 16–27, Santa Barbara (California, USA), May 2001. ACM Press.Google Scholar
- J. D. Ullman. The U. R. strikes back. In Proc. of the ACM Symposium on Principles of Database Systems (PODS), pages 10–22, Los Angeles, (California), March 1982. ACM Press.Google Scholar
- J. D. Ullman. Principles of Database and Kowledge Base Systems, volume II. Computer Science Press, 1989.Google Scholar
- M. Yannakakis. Algorithms for acyclic database schemes. In Proceedings of International Conference on Very Large Data Bases, pages 82–94. Morgan Kaufmann, 1981.Google Scholar
- C. Yu and M. Özsoyoglu. An algorithm for tree-query membership of a distributed query. In Proceedings of IEEE COMPSAC, pages 306–312, 1979.Google Scholar