Answering queries with useful bindings
Answering queries with useful bindings
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使用有用的绑定回答查询
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
E. Chang
中科院分区：
文献类型：
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作者：
Chen Li;E. Chang
在信息整合系统中，来源可能具有多样化且有限的查询功能。为了从这些限制性来源获取最大信息以回答查询，可以访问查询中未指定的来源（即未查询来源）。在本文中，我们提出了一个查询计划框架，以在有限的访问模式的情况下回答查询。在框架中，查询和源描述将转换为递归数据编写程序。然后，我们在此框架中解决了优化问题，包括如何确定是否需要访问Querty源，如何为查询选择有用的来源以及如何测试查询遏制。我们开发了解决这些问题的算法，从而构建了一个有效的程序来回答查询。
In information-integration systems, sources may have diverse and limited query capabilities. To obtain maximum information from these restrictive sources to answer a query, one can access sources that are not specified in the query (i.e., off-query sources). In this article, we propose a query-planning framework to answer queries in the presence of limited access patterns. In the framework, a query and source descriptions are translated to a recursive datalog program. We then solve optimization problems in this framework, including how to decide whether accessing off-query sources is necessary, how to choose useful sources for a query, and how to test query containment. We develop algorithms to solve these problems, and thus construct an efficient program to answer a query.