Related Axis: The Extension to XPath Towards Effective XML Search
Related Axis: The Extension to XPath Towards Effective XML Search
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DOI：
10.1007/s11390-012-1217-0
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发表时间：
2012-01
影响因子：
0.7
通讯作者：
Junfeng Zhou;T. Ling;Z. Bao;Xiaofeng Meng
中科院分区：
文献类型：
--
作者：
Junfeng Zhou;T. Ling;Z. Bao;Xiaofeng Meng
我们研究了现有的XML搜索方法的局限性，并提出了一种新的语义--关联关系，以在没有结构约束的情况下有效地从XML数据中捕获有意义的数据元素关系。然后，我们对XPath进行了扩展，引入了一个新的轴--关联轴，来指定查询节点之间的关联关系，从而增强了XPath的灵活性。我们建议通过一种新的模式摘要来减少计算关联关系的成本，该摘要在没有任何损失的情况下总结了原始模式中的关联关系。在此模式总结的基础上，引入了两个索引来提高查询处理的性能。我们的算法表明，大多数查询的求值操作可以等价地转化为几个选择和值连接操作，从而避免了代价高昂的结构化连接操作。实验结果表明，该方法在关联关系的有效性与已有关键字搜索语义的比较以及评估方法与已有查询引擎的效率比较方面是有效和高效的。
We investigate the limitations of existing XML search methods and propose a new semantics, related relationship, to effectively capture meaningful relationships of data elements from XML data in the absence of structural constraints. Then we make an extension to XPath by introducing a new axis, related axis, to specify the related relationship between query nodes so as to enhance the flexibility of XPath. We propose to reduce the cost of computing the related relationship by a new schema summary that summarizes the related relationship from the original schema without any loss. Based on this schema summary, we introduce two indices to improve the performance of query processing. Our algorithm shows that the evaluation of most queries can be equivalently transformed into just a few selection and value join operations, thus avoids the costly structural join operations. The experimental results show that our method is effective and efficient in terms of comparing the effectiveness of the related relationship with existing keyword search semantics and comparing the efficiency of our evaluation methods with existing query engines.