Distributed query processing in Cronus

Four distributed query processing strategies under consideration for incorporation into the Cronus object-oriented distributed computing environment are described. Under Cronus, object storage can be embedded inside applications, and facilities are provided to distribute and replicate automatically the data maintained by the application. The performance of the query processing strategies is analyzed within this environment. The resulting evaluation points out the factors to consider in developing query processing strategies for replicated, object-oriented data, and the impact of those factors on the cost and optimality of the strategies. The evaluation led to the adoption of an optimistic, decentralized strategy which increases parallelism and decreases the size of messages at the expense of an increase in the number of messages transferred.<>