Fujitsu Corporation

Agency of Industrial Science and Technology

Haruo Yokota

Yasuo Noguchi

Naoki Akaboshi

Katsumi Hayashi

Riichiro Take

Hajime Kitakami

Seigo Hirosue

A parallel sorting system is disclosed, having N (=2.sup.n) processing devices, each of which comprises a sort element storing unit, an inner sorting unit, a transposing unit, and a comparing and substituting unit. In the sort element storing unit, sort elements/N are stored. Sorting process is performed for n stages. In each stage, the inner sorting unit sorts the sort elements, and the transposing unit exchanges sorted elements at a transposing position with another processing device through a network. Thereafter, the comparing and substituting unit compares the two sets of sorts elements. This process sequence is repeated for all stages. And, after the transposing process and the inner sorting process are performed, the sorting process are completed. In this system, the number of communication times is reduced to 2n.

Parallel sorting system to reduce the amount of communication between

A database system including a transaction database system processing device for executing a transaction database process and a decision support database system processing device for executing a decision support process. The database system further includes a transaction database storage device, provided with the transaction database device, for retaining a transaction database created and updated by the transaction database process, a first and second database storage device, each provided with the decision support database device, and each for retaining a first and a second decision database, respectively, for use in a decision support process, a delayed updating device, provided with the decision support database device, for receiving a log created based on the transaction database at each of a predetermined time interval, and for alternatively supplying both the log received at a current predetermined time interval and the log received immediately preceding the current predetermined time interval to the first database storage device and to the second database storage device at each predetermined time interval, and a retrieving device, provided with decision support database device, for executing a retrieving process for the second decision database stored in the second database storage device when the delayed updating device supplies both logs to the first database storage device and for executing a retrieving process for the first decision database stored in the first database storage device when the delayed updating device supplies both logs to the second database storage device.

Database management system to alternately perform retrieval process and

A deadlock detection system each comprise a lock control table having entries corresponding to a resource when a plurality of resource requesters share a plurality of resources, a resource requester identifier list connected to a table of the lock control table, and a lock controller for managing an exclusive control by using the lock control table and the resource requester identifier list and for detecting a deadlock by examining a sequence inversion among resource requester identifiers on a list among competing resource requesters. An element of the resource requester identifier list can distinguish a shared lock from an exclusive lock by transferring a lock list obtained through a breakdown according to the content of a shared lock, and by independently examining the sequence inversion of resource requester identifier of the list among competing resource requesters.

Deadlock detecting system

A multiport memory system has a plurality of data input/output ports, a plurality of memory banks, and a switching network for connecting the ports and the memory banks. A page address is transferred by way of a data line of the switching network and an address calculation is performed in each memory bank so that data can be read out of and written in to continuously via the plurality of ports.

Growing community of inventors

Kawasaki, Japan

Haruo Yokota