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Querying Semistructured Heterogeneous Information

Quass, D. and Rajaraman, A. and Sagiv, Y. and Ullman, J. and Widom, J. (1995) Querying Semistructured Heterogeneous Information. Technical Report. Stanford InfoLab. (Publication Note: 4th International Conference on Deductive and Object-Oriented Databases, Singapore, December 1995 (DOOD 1995).)




Semistructured data has no absolute schema fixed in advance and its structure may be irregular or incomplete. Such data commonly arises in sources that do not impose a rigid structure (such as the World-Wide Web) and when data is combined from several heterogeneous sources. Data models and query languages designed for well structured data are inappropriate in such environments. Starting with a "lightweight" object model adopted for the TSIMMIS project at Stanford, in this paper we describe a query language and object repository designed specifically for semistructured data. Our language provides meaningful query results in cases where conventional models and languages do not: when some data is absent, when data does not have regular structure, when similar concepts are represented using different types, when heterogeneous sets are present, and when object structure is not fully known. This paper motivates the key concepts behind our approach, describes the language through a series of examples (a complete semantics is available in an accompanying technical report [QRS + 94and describes the basic architecture and query processing strategy of the "lightweight" object repository we have developed

Item Type:Techreport (Technical Report)
Uncontrolled Keywords:LORE, tsimmis, semistructured, object-oriented
Subjects:Computer Science > Data Integration and Mediation
Computer Science > Semistructured Data
Related URLs:Project Homepage, Project Homepage,
ID Code:96
Deposited By:Import Account
Deposited On:25 Feb 2000 16:00
Last Modified:05 Feb 2009 15:03

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