Date Added: Mar 2013
The problem of finding an optimal strategy to minimize the data transmission cost in distributed database systems, even with the one join attribute is a NP-Hard problem. Determining the optimal sequence of join operations in query optimization leads to exponential complexity. To deal with such a problem, there is need to develop a heuristic approach to solve the problem in polynomial time. This paper mentioned the use of semi-join operation. Beneficial Semi-join operation reduces the amount of data transmission required to perform the join sequences. This paper addresses the optimization of queries with one and more than one join attributes.