Operator implementation of Result Set Dependent KWS scoring functions

The above strategies have been implemented on a PostgreSQL codebase, inclusive of integration with the optimizer for the operator approach. A detailed empirical study over real-world data sets, including DBLP and Wikipedia, indicates that the wrapper approach addresses the RSD efficiency issue to a limited extent only. More encouragingly, the operator approach is extremely successful, delivering processing times that are comparable to, or better than, those of non-RSD implementations. We expect these results to aid in the organic hosting of KWS functionality on database systems.