Effective XML Keyword Search with Nearest Common Object Node Semantics
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Date
2012-09-20
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Abstract
Lowest Common Ancestor (LCA) semantics and its extensions such as SLCA, MLCA, VLCA and ELCA. However, these approaches commonly do not return a complete answer set for a query because they can only find the common ancestors of a set of
keywords but cannot find their common information appearing at their descendants in an XML document.
In this paper, we introduce a new semantics, called Nearest Common Objects Node (NCON), which guarantees that both common ancestors and common descendants are included in the answer set for a query and therefore enables us to answer a query
more completely. We also propose an NCON-based approach for XML keyword search, which exploits not only the index of the original XML document, but also the index of its reversed XML document, and devise optimization techniques to facilitate the process of finding NCONs.
We have developed XComplete, a system for our NCON-based approach, which essentially uses the NCON semantics and post-processing techniques, altogether enable XComplete to return an answer set with completeness, meaningfulness, no irrelevance, no duplicate and comprehension to users. The results of our extensive experiments show that our proposed approach outperforms the existing LCA-based approaches in terms of both
effectiveness and efficiency.