Abstract: A storage comprising an object access module for the shared part for implementing advanced I/O provides an interface for registering and deleting object description data declaring how to store objects within a second storage, in order to reduce the development cost of modules for implementing functions. Also, in order to reduce the total cost of ownership, modules are transferred to the storage through a management computer. The present invention allows the storage for contiguously providing functions effective to a vast range of applications to be provided with lower development cost as well as lower total cost of ownership.

Abstract: A shared-nothing database management system employs a method of adding and removing a database server without significantly affecting the processing performance for accessing a table from a user or an application. A scheduler module creates a schedule which separately handles the addition of a CPU resource and the addition of a storage I/O resource, and a server is added in accordance with the created schedule. A common disk is used to remove a disk at an arbitrary timing. Further, a data region is previously subdivided on the common disk to eliminate a movement of data associated with the addition of a server.

Abstract: In a communicating method between data processing apparatuses using the Sockets API or the MPI API, the apparatus on the receiving side informs the apparatus on the sending side of a data length threshold, which makes the apparatus on the sending side to decide between sending data to a pre-registered pre-allocated buffer on the apparatus on the receiving side, or having the memory region that is the final destination of the data transfer registered and then sending the data to this memory region. When the length of the data to be sent does not exceed the threshold, sending to the pre-allocated buffer is selected, and the data transfer operation is completed by copying the received data from the pre-allocated buffer to the final destination of this transfer. In case the length of the data to be sent exceeds the threshold, the data is sent directly to the final destination of this transfer.

Abstract: The present invention aims to dynamically re-configure hosts and storage in a shared-nothing database. In the shared-nothing database, processes 24 to 29 executed in the hosts 11 to 14 access data of a storage device 30. A system manager 70 and a database manager 10 manage the hosts 11 to 14 and the storage device 30. The processes 24 to 29 access one or more disks 51 to 54 of the storage device. To add or reduce the number of the hosts, the processes 24 to 29 are reassigned among the hosts 11 to 14.

Abstract: A data request analysis unit for accepting and analyzing a request from a client computer, a data conversion program generation unit, and a data conversion unit are provided in a magnetic disk apparatus, the data conversion program generation unit downloads a program module by way of a network as required based on the analysis result obtained by use of the data request analysis unit to generate a data conversion program, and the data conversion unit downloads the conversion program, and converts the type of the data read out from the magnetic memory medium by use of the program, and directly transfers the converted data to the client computer by way of a network interface, thereby, the present invention provides a general purpose magnetic disk apparatus which is capable of flexibly accommodating the request from the client computer, the scalability of the whole system is improved because the data is converted in the magnetic disk apparatus, and the process efficiency of the client computer is improved.