Patent ID: 7558802
Filing Date: 2009-07-07
Classification: G06F,Y10S

Abstract:
1. An index managing method used in an information retrieving system, said method comprising the steps of: when said information items are registered as said search-targeted ranges in said information retrieving system, said information retrieving system being constructed to have n retrieval nodes to which n divided search-targeted ranges of information that is formed of a plurality of information items of search-targeted range are respectively allocated, n divided indexes respectively corresponding to said n retrieval nodes resulting from dividing for said respective retrieval nodes, and n storages for storing said indexes respectively corresponding to said n retrieval nodes and to cause said plurality of retrieval nodes to simultaneously make information retrieval with an index searcher provided in each of said plurality of retrieval nodes by using said indexes, wherein said indexes are formed of an inverted file that has index keys and a list of address of each said information items corresponding to said index keys, when the allocation of said search-targeted range in said information retrieving system is changed, extracting one of a plurality of index key values by use and one of the information items and addresses thereof thereby to provide an index information entry as a corresponding pair; logically dividing said index information into n buckets (m>n); and preprocessing each of said buckets of said index information entry so as to make a closed processing within each bucket, thereby producing a partial inverted file as another corresponding pair; and storing said partial inverted file as said another corresponding pair; and when the allocation of said search-targeted ranges to said retrieval nodes is changed, altering the allocation of said buckets to said retrieval nodes; and generating said indexes at said retrieval nodes by using said stored partial inverted file as said another corresponding pair corresponding to n or a plurality of ones of said buckets allocated to said retrieval nodes at the time of said allocation change.