Querying Web-Accessible Life Science Sources: Which paths to choose?

Web-accessible life sciences sources are characterized by a complex graph of overlapping sources, and multiple alternate links between sources. A (navigational) query may be answered by traversing multiple alternate paths between a start source and a target source. Each of these paths may have dissimilar benefit, e.g., the cardinality of result objects that are reached in the target source. Paths may also have dissimilar costs of evaluation, i.e., the execution cost of a query evaluation plan for a path. Finally, since the result objects of alternate paths may overlap, the combined benefit of two paths are not independent. In this context, we present two problems. The first problem is to determine the K-best paths or Relevant Paths with low cost and high benefit. The second problem is to choose a good combination of top-k (possibly overlapping) paths. While the first problem regards paths individually and finds the best ones among a vast number of paths, the second problem assesses the integrated result of a set of paths. Further, we discuss the interrelation between the two problems and motivate the importance of a practical solution.