Semantics Analysis for XML Keyword Search

Abstract

Since existing approaches for XML keyword search only rely on the structure of XML but do not consider the semantics of objects, relationships and attributes (ORA-semantics), they may suffer from several problems, including meaningless answers, missing answers, duplicated answers, schema-dependent answers, and incomplete answers. To address the above problems, we propose to use ORA-semantics. Particularly, we first introduce novel search semantics, called NCON (Nearest Common Object Node) for XML keyword search over an XML document with no IDREF. We then propose a new search strategy which can extend our NCON semantics for an XML document with IDREFs, modeled as an XML IDREF graph, by exploiting the hierarchy of XML IDREF graph. Especially, we further extend the NCON semantics by returning so-called common relatives of matching nodes to provide an independent-schema XML keyword search approach. Finally, we support XML keyword queries with group-by and aggregate functions.