On the Integration of Structure Indexes and Inverted Lists

Abstract

We consider the problem of how to combine structure indexes and inverted lists to answer queries over a native XML DBMS, where the queries specify both path and keyword constraints. We augment the inverted list entries to integrate them with a given structure index. We give novel algorithms for evaluating branching path expressions. Our experiments show the benefit of integrating the two forms of indexes. We also consider the problem of incorporating relevance ranking into path expression queries. By integrating the above techniques with the Threshold Algorithm proposed by Fagin et al., we obtain instance optimal algorithms to push down top k computation.