Heuristic containment check of partial tree-pattern queries in the presence of index graphs

The wide adoption of XML has increased the interest of the database community on tree-structured data management techniques. Querying capabilities are provided through tree-pattern queries. The need for querying tree-structured data sources when their structure is not fully known, and the need to integrate multiple data sources with different tree structures have driven, recently, the suggestion of query languages that relax the complete specification of a tree pattern. In this paper, we use a query language which allows partial tree-pattern queries (PTPQs). The structure in a PTPQ can be flexibly specified fully, partially or not at all. To evaluate a PTPQ, we exploit index graphs which generate an equivalent set of "complete" tree-pattern queries. In order to process PTPQs, we need to efficiently solve the PTPQ satisfiability and containment problems. These problems become more complex in the context of PTPQs because the partial specification of the structure allows new, n...

• Type: Conference
• Year: 2006
• Where: CIKM
• Authors: Dimitri Theodoratos, Stefanos Souldatos, Theodore Dalamagas, Pawel Placek, Timos K. Sellis
• Keywords: CIKM 2006, Index Graph, Information Management, Tree-pattern Queries, Tree-structured Data