Effective XML Keyword Query Processing

Keyword search query processing is considered as the most promising way of information retrieval over XML data in present days as it relieves user from understanding complex schemas of XML document and writing difficult queries using XPath and XQuery. Till date various query processing techniques have been proposed to get meaningful results through keyword search using LCA (Lowest Common Ancestor) semantic under tree based approach. Amongst many such LCA based techniques which have been proposed to get more accurate and meaningful results SLCA (Smallest LCA) and ELCA (Exclusive LCA), have considered being the most popular ones. However due to AND-semantic constraints of LCA based techniques, SLCA or ELCA results into NULL for keyword queries involving missing elements and provides unintended results if the technique returns root element of the document. To address these issues, we propose an effective XML keyword query processing technique. In this paper we present the proposed technique based on ELCA query semantic which returns the meaningful results when ELCA based technique results into NULL or document root element thereby providing better information discovery over XML data. The proposed technique can also be applied to SLCA based techniques to get similar SLCA based meaningful results.