Updating an indexing tables in a database system comprising a database storing item tables of items appended by timestamps. Each of items is further categorized by timestamp into said tables, and said item tables being indexed by indexing data. The database system further comprises an indexing table for said indexing data, listing the earliest timestamp of said item table together with said indexing data and a system manager for searching said item tables using said indexing table and a maintenance module for said indexing table.