Views for Semistructured
نویسندگان
چکیده
Deening a view over a semistructured database introduces many new problems. In this paper we propose a view speciication language and consider the problem of answering queries posed over views. The two main approaches, query rewriting and view materialization, are outlined with focus on the diicult problems caused by the semistructured nature of the data.
منابع مشابه
Query Rewriting using Semistructured Views
We consider the problem of rewriting semistructured queries using semistructured views. Given a client semistructured positive non-recursive query and a set of semistructured views, the algorithm nds a rewriting query that is equivalent to the client query and accesses only the views. Our solution is based on appropriately generalizing well understood techniques such as containment mappings and...
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Existing systems that support semistructured views do not maintain semantics during the process of designing the views. Thus, these systems do not guarantee the validity and reversibility of the views. In this paper, we propose an approach to address the issue of valid and reversible semistructured views. We design a set of view operators for designing semistructured views. These operators are ...
متن کاملViews for Semistructured Data
De ning a view over a semistructured database introduces many new problems. In this paper we propose a view speci cation language and consider the problem of answering queries posed over views. The two main approaches, query rewriting and view materialization, are outlined with focus on the di cult problems caused by the semistructured nature of the data.
متن کاملIncremental Maintenance for Materialized Views over Semistructured Data
Semistructured data is not strictly typed like relational or object-oriented data and may be irregular or incomplete. It often arises in practice, e.g., when heterogeneous data sources are integrated or data is taken from the World Wide Web. Views over semistructured data can be used to lter the data and to restructure (or provide structure to) it. To achieve fast query response time, these vie...
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تاریخ انتشار 1997