Query Planning in the Presence of Overlapping Sources

Navigational queries on Web-accessible life science sources pose unique query optimization challenges. The objects in these sources are interconnected to objects in other sources, forming a large and complex graph, and there is an overlap of objects in the sources. Answering a query requires the traversal of multiple alternate paths through these sources. Each path can be associated with the benefit or the cardinality of the target object set (TOS) of objects reached in the result. There is also an evaluation cost of reaching the TOS. We present dual problems in selecting the best set of paths. The first problem is to select a set of paths that satisfy a constraint on the evaluation cost while maximizing the benefit (number of distinct objects in the TOS). The dual problem is to select a set of paths that satisfies a threshold of the TOS benefit with minimal evaluation cost. The two problems can be mapped to the budgeted maximum coverage problem and the maximal set cover with a thresho...

• Type: Conference
• Year: 2006
• Where: EDBT
• Authors: Jens Bleiholder, Samir Khuller, Felix Naumann, Louiqa Raschid, Yao Wu
• Keywords: Database, EDBT 2006, Evaluation Cost, Maximal Set Cover, Multiple Alternate Paths