A B tree index for a full-text search through documents is created fast and fast searches are implemented using the index. A B tree index to register sets of words serving as keys and documents containing the words is constituted of a plurality of B tree subindexes; a document identification number id...http://www.google.de/patents/US6678687?utm_source=gb-gplus-sharePatent US6678687 - Method for creating an index and method for searching an index
