A heuristic approach for checking containment of generalized tree-pattern queries

Query processing techniques for XML data have focused mainly on tree-pattern queries (TPQs). However, the need for querying XML data sources whose structure is very complex or not fully known to the user, and the need to integrate multiple XML data sources with different structures have driven, recently, the suggestion of query languages that relax the complete specification of a tree pattern. In order to implement the processing of such languages in current DBMSs, their containment problem has to be efficiently solved. In this paper, we consider a query language which generalizes TPQs by allowing the partial specification of a tree pattern. Partial tree-pattern queries (PTPQs) constitute a large fragment of XPath that flexibly permits the specification of a broad range of queries from keyword queries without structure, to queries with partial specification of the structure, to complete TPQs. We address the containment problem for PTPQs. This problem becomes more complex in the contex...

• Type: Conference
• Year: 2008
• Where: CIKM
• Authors: Pawel Placek, Dimitri Theodoratos, Stefanos Souldatos, Theodore Dalamagas, Timos K. Sellis
• Keywords: CIKM 2008, Information Management, Partial Specification, XML Data, XML Data Sources