Hash tables are used to index an internal database--one that resides in primary memory. The hash tables are segmented into a sequence of segments that increase geometrically in size. To expand a table, an additional segment is allocated which is twice as large as the previously allocated segment. This...http://www.google.de/patents/US6067547?utm_source=gb-gplus-sharePatent US6067547 - Hash table expansion and contraction for use with internal searching
