A Transmission Cost Model of Data Retrieval from a Cluster System on an One Node One-Fragment, One-Node One-Task and Random Allocation Environment using no Global Directory

摘要

Parallel database processing on cluster system is an outstanding high-performance approach for large database accesses since parallel tasks can access data simultaneously, which can significantly shorten total system waiting time and turnaround time. To achieve this, fragment and task allocations are the two most complex key issues in developing and using such a huge system. They significantly affect database access efficiency and transmission costs. Therefore, optimizing the two allocations is one of the most important tasks in designing a parallel database. In this article, we analyze transmission costs generated by cluster database accesses under an one-node one-fragment, one-node one-task and random allocation environment. The probability density function and the expected value of the transmission cost of the environment are addressed and explored.