Fixed-length data (560) contained in a database (560) are segmented into a number of pieces of data that are searchable at a time and searching is performed at high speed. As means for it, a pointer table (500), a secondary pointer table, a local table, and a fixed-length-data table are provided, and when more segmentation is required, a table having a numeric-value comparing function is further provided. As means for performing efficient configuration/management of the tables and for performing management that does not interfere with a search operation, an empty-house table (700), an empty-room table (720), a room-management table (740), and a structure-management table (760) may be provided.