Design and evaluation of database multiprocessor architecture with high data availability

A three-level hierarchical multiprocessor database architecture, which can provide high reliability and data availability is proposed and studied. This hierarchical architecture is a combination of Omega-clusters connected in a shared-nothing manner. The Omega-cluster is a combination of four two-processor shared-memory units and one disk subsystem unit. This architecture has been used for designing the Omega parallel database machine. The paper describes a general architecture of the Omega system and some novel concepts which were used in the Omega implementation. We implemented and tested the proposed architecture under various system and database conditions. The experimental results indicate that the performance of the Omega-clusters can be very similar to the performance of the shared-everything clusters, even when the data are skewed