PERFORMANCE ANALYSIS OF THE SEND-ON-DEMAND - A DISTRIBUTED DATABASE CONCURRENCY-CONTROL PROTOCOL FOR HIGH-SPEED NETWORKS

In this paper, we consider an application of high-speed wide area netw orks, viz. that of distributed database systems (DDBS). In a high-spee d environment, although the transmission delay decreases, the propagat ion delay (communication latency) now becomes the throughput thwarting factor. Existing Concurrency Control (CC) protocols do not address th e communication latency problem. This paper is a continuation of our r esearch work in this area. First, we very briefly summarize our previo usly reported research results, viz. the issues that are important for DDBS in high-speed wide area networks, and the description of a new C C protocol called 'send-on-demand'. A detailed comparison of this prot ocol with that of locking is provided, using analytical and simulation techniques. The datacycle scheme performs very well in a read-oriente d environment, and the rest of the paper deals with developing and com paring hybrid CC schemes using datacycling for queries. Altogether, th e performance of four concurrency control schemes is compared.