Patent ID: 7558786
Filing Date: 2009-07-07
Classification: G06F,Y10S

Abstract:
1. A database search method in a database system, said database system comprising a computer including a CPU, a memory, and a storage device, said database being stored in said storage device, said database search method making said computer execute the steps of: storing parts tables of items appended by timestamps in a database, including parts table identifiers, and storing items in an indexing table in which the update time and parts table identifier are stored, said parts tables being indexed by indexing data, said database and said parts tables being updatable by appending only, categorizing said items by timestamp and parts table identifier into said parts tables, and indexing said parts tables by indexing data such that time differential between given items is correlated to time differential between indexing data corresponding to said given items, appending said database with items from a second database when a predetermined number of new items becomes available in said second database, storing an indexing table for said indexing data, listing a newest timestamp of said parts tables together with said indexing data, searching for a target item from said indexing table among said items from said parts tables, repairing said indexing table with respect to time evolution by a maintenance module, said maintenance module executing further steps of: executing a binary search of said database with referring said indexing table, determining whether or not an appending of records of said indexing table is required depending on search keys, and depending on said determination step, if said appending is required, calling a repairing function so as to append said update records while executing said binary search.