Mermaid - Experiences with Network operation

[[abstract]]AIDA is a distributed data management (DDM) front-end system which runs on top of existing databases stored in different data management systems (DBMSs): it appears to the user to be a distributed DBMS, although many of the DBMS functions are actually provided by the underlying DBMS. It currently runs above three relational DBMSs, the IDM database machine connected to a VAX, Ingres on two Suns, and Mistress on a third Sun. One of the key components of the AIDA system is Mermaid, which provides query optimization, networking, and system control. Mermaid required research into query optimization; the costs of operations on the different processors and DBMSs are variable, the network cost is variable, and the capabilities of the different DBMSs are variable. Existing distributed query optimization algorithms were extended to support replicated and fragmented relations. Experiences with the development and testing of the Mermaid system and with the integration of Mermaid with the AIDA translator are reported. The types of commands, the system controller, and experiences with distributed debugging are discussed. Results of initial performance tests are included[[fileno]]2030208030101[[department]]資訊工程學