Abstract: A database management system includes: a hierarchical database including one primary database, an intermediate database, and end databases; and a searching unit which searches, from registered data in the hierarchical database, for matching data which matches a search criterion. At least the end databases store plural pieces of the registered data. The primary database or the intermediate database includes a virtual data table in which search paths are grouped by common information relating to the plural pieces of the registered data. The search paths lead to the registered data stored in: a next-lower database; or the intermediate database or the end database, each being indirectly connected to the primary database or the intermediate database through the next-lower database. The searching unit adopts, as a starting point of a search, the intermediate database or the end database which involves the common information contained in the search criterion.

Abstract: A database management system according to one embodiment includes at least one processor configured to control a hierarchical database including a plurality of end databases and a primary database directly or indirectly connected to the plurality of end databases. Each of the plurality of end databases stores sensor data. The primary database provides a virtual data table. The at least one processor transmits, to the end database, a search instruction for obtaining a result set containing a combination of an intermediate result based on the sensor data and a path ID for uniquely identifying a path connecting the primary database and the end database, receives a result set, and represents a search result based on the result set by the virtual data table and outputs the search result.

Abstract: A database management system according to one embodiment includes at least one processor configured to control a hierarchical database including a plurality of end databases and a primary database directly or indirectly connected to the plurality of end databases. Each of the plurality of end databases stores sensor data. The primary database provides a virtual data table. The at least one processor transmits, to the end database, a search instruction for obtaining a result set containing a combination of an intermediate result based on the sensor data and a path ID for uniquely identifying a path connecting the primary database and the end database, receives a result set, and represents a search result based on the result set by the virtual data table and outputs the search result.