Abstract: A method of shortening a lock period of a shared buffer in a data processing system includes a step of securing a copy memory used when nonvolatilizing the contents of the shared buffer, a step of temporarily locking the shared buffer, a step of copying the contents of the shared buffer into the copy memory, a step of unlocking the shared buffer after the completion of the copying step and a step of nonvolatilizing the contents of the copy memory. The shared buffer is locked before the contents thereof are copied into the copy memory and is unlocked after the completion of the copying step and before the nonvolatilization of the contents of the copy memory.

Abstract: In a data base processing system using a multiprocessor system, the data base processing system includes: a storage unit provided in the shared memory for storing data base management information representing either an object of a shared processing operation or an object of a local processing operation for every resource; an access management unit provided in each of the processor modules for performing an access control for an access request to the data base under either the shared processing operation or the local processing operation in accordance with the data base management information, the shared processing operation being symmetrically performed, and the local processing operation being asymmetrically performed in each processor module; and a control unit provided in the processor module for controlling the shared/local conversion in such a way that: an access state of the resource is managed for every resource; when a frequency of the access is unevenly distributed to a particular processor module, t