Abstract: A system including multiple application servers for accessing shared data and a centralized control unit for centrally controlling a lock applied to the shared data by each of the application servers. Each application server includes a distributed control unit for controlling a lock applied to the shared data by the application server and a selection unit for selecting any one of distributed mode in which a lock is acquired from the distributed control unit or a centralized mode in which a lock is acquired from the centralized control unit.

Abstract: A system including multiple application servers for accessing shared data and a centralized control unit for centrally controlling a lock applied to the shared data by each of the application servers. Each application server includes a distributed control unit for controlling a lock applied to the shared data by the application server and a selection unit for selecting any one of distributed mode in which a lock is acquired from the distributed control unit or a centralized mode in which a lock is acquired from the centralized control unit.

Abstract: A system including multiple application servers for accessing shared data and a centralized control unit for centrally controlling a lock applied to the shared data by each of the application servers. Each application server includes a distributed control unit for controlling a lock applied to the shared data by the application server and a selection unit for selecting any one of distributed mode in which a lock is acquired from the distributed control unit or a centralized mode in which a lock is acquired from the centralized control unit.

Abstract: A system and method for improving access efficiency in a database. The database stores values of a plurality of keys associated with the respective keys. The system of the invention executes a plurality of transactions on the database, and acquires and records a referenced value which is a value of a key referenced in a corresponding transaction from the database according to the execution of each of the transactions. Then, according to commit requests of the plurality of transactions, the system requests a reply of a resultant table including an arrangement of judgment results obtained by judging whether the value of the key stored in the database is maintained as the referenced value without change made by another transaction for the respective transactions. The system further judges whether each transaction is successful, based on the resultant table sent back and commits only transactions judged to be successful.

Abstract: A system, a program product and an associated method is provided for data processing management in a computing environment having at least a processor. The method comprises creating in the memory an invalidation index having a plurality of rows, each row further comprising a search key field, an ID list field for IDs of records associated with the database, and a count value field. Every time a new reference query is received the processor searches for a row in said invalidation index with an already created search key and then decreases count value of a counter when a match is found and when a match is not found creating a new search key and a new row in an associated invalidation index for said new key.

Abstract: A primary server transmits a write transaction to N backup devices. Each backup device records the write transaction to a local redo log stored at a high-performance storage and then transmits a notification to the primary device. When the primary device receives notifications from M of the N backup devices, it commits the write transaction, recording it to a low-performance storage. Once the write transaction has been recorded to the low-performance storage, the primary device requests that the backup devices delete their logs. If the primary device incurs a fault, one of the backup devices becomes the new primary device and determines which backup device has the newest local redo log. The backup device having the newest log sends it to the other backup devices, which update their local redo logs to the same state as the newest log. Thereafter, the new primary device is ready to resume transaction processing.

Abstract: A system including multiple application servers for accessing shared data and a centralized control unit for centrally controlling a lock applied to the shared data by each of the application servers. Each application server includes a distributed control unit for controlling a lock applied to the shared data by the application server and a selection unit for selecting any one of distributed mode in which a lock is acquired from the distributed control unit or a centralized mode in which a lock is acquired from the centralized control unit.

Abstract: A system and method for improving access efficiency in a database. The database stores values of a plurality of keys associated with the respective keys. The system of the invention executes a plurality of transactions on the database, and acquires and records a referenced value which is a value of a key referenced in a corresponding transaction from the database according to the execution of each of the transactions. Then, according to commit requests of the plurality of transactions, the system requests a reply of a resultant table including an arrangement of judgment results obtained by judging whether the value of the key stored in the database is maintained as the referenced value without change made by another transaction for the respective transactions. The system further judges whether each transaction is successful, based on the resultant table sent back and commits only transactions judged to be successful.

Abstract: A method and system for maintaining consistency between a view of a virtual table and the database. The method includes: First, selecting a discard candidate instance from a discard candidate list table in accordance with an LRU algorithm if it is judged that there is less free space for adding an instance. Then, judging whether a revision wait flag is on for the discard candidate instance. If it is judged that the revision wait flag is on, deleting the discard candidate instance from the discard candidate list table. If it is judged that the revision wait flag is not on, deleting the discard candidate instance from the instance pool and adding the instance to the instance pool. Lastly, adding the requested instance to the instance pool if it is judged that there is enough storage area.

Abstract: A primary server transmits a write transaction to N backup devices. Each backup device records the write transaction to a local redo log stored at a high-performance storage and then transmits a notification to the primary device. When the primary device receives notifications from M of the N backup devices, it commits the write transaction, recording it to a low-performance storage. Once the write transaction has been recorded to the low-performance storage, the primary device requests that the backup devices delete their logs. If the primary device incurs a fault, one of the backup devices becomes the new primary device and determines which backup device has the newest local redo log. The backup device having the newest log sends it to the other backup devices, which update their local redo logs to the same state as the newest log. Thereafter, the new primary device is ready to resume transaction processing.

Abstract: A primary server transmits a write transaction to N backup devices. Each backup device records the write transaction to a local redo log stored at a high-performance storage and then transmits a notification to the primary device. When the primary device receives notifications from M of the N backup devices, it commits the write transaction, recording it to a low-performance storage. Once the write transaction has been recorded to the low-performance storage, the primary device requests that the backup devices delete their logs. If the primary device incurs a fault, one of the backup devices becomes the new primary device and determines which backup device has the newest local redo log. The backup device having the newest log sends it to the other backup devices, which update their local redo logs to the same state as the newest log. Thereafter, the new primary device is ready to resume transaction processing.

Abstract: A primary server transmits a write transaction to N backup devices. Each backup device records the write transaction to a local redo log stored at a high-performance storage and then transmits a notification to the primary device. When the primary device receives notifications from M of the N backup devices, it commits the write transaction, recording it to a low-performance storage. Once the write transaction has been recorded to the low-performance storage, the primary device requests that the backup devices delete their logs. If the primary device incurs a fault, one of the backup devices becomes the new primary device and determines which backup device has the newest local redo log. The backup device having the newest log sends it to the other backup devices, which update their local redo logs to the same state as the newest log. Thereafter, the new primary device is ready to resume transaction processing.

Abstract: The present invention makes it possible to perform a black-box test even on a system in which relationships between inputs and outputs cannot uniquely be determined, by enabling analysis of a cause-effect relation (dependency) between a state of an object and a state of another object in a program, thereby analyzing the cause-effect relation between the input and the output in the test.