ABSTRACT
We study models of incomplete information for XML, their computational properties, and query answering. While our approach is motivated by the study of relational incompleteness, incomplete information in XML documents may appear not only as null values but also as missing structural information. Our goal is to provide a classification of incomplete descriptions of XML documents, and separate features - or groups of features - that lead to hard computational problems from those that admit efficient algorithms. Our classification of incomplete information is based on the combination of null values with partial structural descriptions of documents. The key computational problems we consider are consistency of partial descriptions, representability of complete documents by incomplete ones, and query answering. We show how factors such as schema information, the presence of node ids, and missing structural information affect the complexity of these main computational problems, and find robust classes of incomplete XML descriptions that permit tractable query evaluation.
- S. Abiteboul, O. Duschka. Complexity of answering queries using materialized views. In PODS 1998, pages 254--263. Google Scholar
Digital Library
- S. Abiteboul, P. Kanellakis, G. Grahne. On the representation and querying of sets of possible worlds. TCS 78 (1991), 158--187. Google Scholar
Digital Library
- S. Abiteboul, L. Segoufin, V. Vianu. Representing and querying XML with incomplete information. ACM TODS, 31 (2006), 208--254. Google Scholar
Digital Library
- S. Abiteboul, R. Hull and V. Vianu. Foundations of Databases, Addison Wesley, 1995. Google Scholar
Digital Library
- M. Arenas, W. Fan, L. Libkin. On the complexity of verifying consistency of XML specifications. SIAM J. Comput. 38 (2008), 841--880. Google Scholar
Digital Library
- M. Arenas, L. Libkin. XML data exchange: consistency and query answering. J. ACM 55(2): (2008). Google Scholar
Digital Library
- M. Benedikt, W. Fan, F. Geerts. XPath satisfiability in the presence of DTDs. J. ACM 55(2): (2008). Google Scholar
Digital Library
- H. Bjorklund, W. Martens, T. Schwentick. Conjunctive query containment over trees. DBPL'07, pages 66--80. Google Scholar
Digital Library
- H. Bjorklund, W. Martens, T. Schwentick. Optimizing conjunctive queries over trees using schema information. MFCS'08, pages 132--143. Google Scholar
Digital Library
- A. Cali, D. Lembo, R. Rosati. On the decidability and complexity of query answering over inconsistent and incomplete databases. PODS'03, pages 260--271. Google Scholar
Digital Library
- D. Calvanese, G. De Giacomo, M. Lenzerini. Semi-structured data with constraints and incomplete information. Description Logics, 1998.Google Scholar
- D. Calvanese, G. De Giacomo, M. Lenzerini. Representing and reasoning on XML documents: a description logic approach. J. Log. Comput. 9 (1999), 295--318.Google Scholar
Cross Ref
- S. Cohen, B. Kimelfeld, Y. Sagiv. Incorporating constraints in probabilistic XML. In PODS'08, pages 109--118. Google Scholar
Digital Library
- C. David. Complexity of data tree patterns over XML documents. In MFCS'08, pages 278--289. Google Scholar
Digital Library
- A. Deutsch, V. Tannen. Reformulation of XML queries and constraints. In ICDT'03, pages 225--241. Google Scholar
Digital Library
- Document Object Model (DOM). W3C Recommendation, April 2004. http://www.w3.org/TR/DOM--Level--3--Core.Google Scholar
- R. Fagin, Ph. Kolaitis, R. Miller, L. Popa. Data exchange: semantics and query answering. TCS 336(1): 89--124 (2005). Google Scholar
Digital Library
- P. Gardner, G. Smith, M. Wheelhouse, U. Zarfaty. Local Hoare reasoning about DOM. In PODS'08, pages 261--270. Google Scholar
Digital Library
- G. Gottlob, C. Koch, K. Schulz. Conjunctive queries over trees. J. ACM 53 (2006), 238--272. Google Scholar
Digital Library
- T. Imielinski, W. Lipski. Incomplete information in relational databases. J. ACM 31 (1984), 761--791. Google Scholar
Digital Library
- Y. Kanza, W. Nutt, Y. Sagiv. Querying incomplete information in semistructured data. JCSS 64 (2002), 655--693.Google Scholar
Digital Library
- Ph. Kolaitis and M. Vardi. A logical approach to constraint satisfaction. In Finite Model Theory and its Applications, Springer 2007, pages 339--370.Google Scholar
Cross Ref
- M. Lenzerini. Data integration: a theoretical perspective. In PODS'02, pages 233--246. Google Scholar
Digital Library
- D. Olteanu, C. Koch, L. Antova. World-set decompositions: expressiveness and efficient algorithms. TCS 403 (2008), 265--284. Google Scholar
Digital Library
- T. Schwentick. A little bit infinite? On adding data to finitely labelled structures. In STACS'08, pages 17--18.Google Scholar
- L. Segoufin. Automata and logics for words and trees over an infinite alphabet. In CSL'06, pages 41--57. Google Scholar
Digital Library
- P. Senellart, S. Abiteboul. On the complexity of managing probabilistic XML data. In PODS'07, pages 283--292. Google Scholar
Digital Library
- M. Vardi. Querying logical databases. JCSS 33 (1986), 142--160. Google Scholar
Digital Library
Index Terms
XML with incomplete information: models, properties, and query answering
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