Optimizing the number of processing nodes and I/O nodes in a shared disk parallel database system: SPAX

In a shared disk architecture such as a SPAX system, messages for concurrency/coherency control and data transmission due to disk sharing degrade the system performance. But the network speed in a SPAX system is sufficiently fast, and network traffic does not deteriorate the system performance. However, the number of processing nodes and that of I/O nodes for disk I/O can be a bottleneck in the SPAX system. The authors study the effect of the number of processing nodes and I/O nodes on the system performance.