This thesis presents a new approach to optimize join processing in the environment where relations are horizontally fragmented over a broadcast local area network. A number of approach in the literature attempted this sort of optimization, but they lack the overhead of subjoin result collection time due to unaccurate estimation of the subjoin result. The unaccurateness of estimation could be a reason of the response time delay of the join processing. Previous approaches, moreover, did not consider the subjoin migration from a site to the assembly site, that causes the problems of redundant transmission of data and the subjoin iteration.
The proposed new approach, named Subjoin Coordinator Resignation (SCR) approach, optimize the response time of fragmented join processing by considering the subjoin result collection time. SCR eliminates the redundant transmission of data with the extra copy of transmitted data. SCR also reduces the subjoin iteration time with the current tuple positions of each fragment and intermediate subjoin result.
