Evaluation of iceberg distance joins

Abstract

The iceberg distance join returns object pairs within some distance from each other, provided that the first object appears at least a number of times in the result, e.g., "find hotels which are within 1km to at least 10 restaurants". The output of this query is the subset of the corresponding distance join (e.g., "find hotels which are within 1km to some restaurant") that satisfies the additional cardinality constraint. Therefore, it could be processed by using a conventional spatial join algorithm and then filtering-out the non-qualifying pairs. This approach, however, is expensive, especially when the cardinality constraint is highly selective. In this paper, we propose output-sensitive algorithms that prune the search space by integrating the cardinality with the distance constraint. We deal with cases of indexed/non-indexed datasets and evaluate the performance of the proposed techniques with extensive experimental evaluation covering a wide range of problem parameters. © Springer-Verlag Berlin Heidelberg 2003.