Engineering efficient metric indexes

We give efficient algorithms and index data structures for range search in general metric spaces. We give a simple methods to make almost any existing algorithm memory adaptive, improving the search the more memory is available. For vector spaces and metric space of strings we show how several distances can be computed in bit-parallelly, in sequential computer, and use the result to improve the search performance. This method works especially well with approximate range queries. The experimental results show that we can obtain order of magnitude improvements over the existing methods.