US Patent 7783589 Inverted index processing

Systems and methods for improving indexing are described. In one exemplary method, a 2-level table is used to improve performance when searching an index. A first table contains a subset of more frequently occurring terms and a second and larger table contains terms that occur rarely, with the first table optimized for updating and the second table optimized for searching. The second table is searched only when a search of the first table is unsuccessful. Other methods are described and data processing systems and machine readable media are also described.