Processing Recursive XQuery over XML Streams: The Raindrop Approach

— XML stream applications bring the challenge of efficiently processing queries on sequentially accessible tokenbased data. For efficient processing of queries, we need to ensure that memory usage stays low. This in turn requires that we avoid holding data in the query buffer, by outputting it at the earliest possible time. In this paper, we propose a new class of stream algebra operators for efficient recursive XQuery stream processing. In particular we propose two strategies for implementing structural joins: (a) the just-in-time structural join strategy efficiently processes joins as long as the input XML substreams are non-recursive and (b) the recursive structural join strategy supports structural joins over recursive XML substreams, however at an added cost of tuple-level ID-comparisons. Both structural join strategies are complemented by an automatadriven invocation mechanism that triggers the execution of the join at the first possible moment upon recognizing the end of ...

• Type: Conference
• Year: 2006
• Where: ICDE
• Authors: Mingzhu Wei, Ming Li, Elke A. Rundensteiner, Murali Mani
• Keywords: Database, ICDE 2006, Stream, Structural Join, Structural Join Strategy