Optimization of Multi-way Join Cost Using System R* and SharesSkew

摘要

In a distributed environment relations are stored at different sites. To perform algebraic operations such as join, the relations are to be transferred from one site to the other in such a way that the total communication cost is minimized. This paper deals with the problem of computing the transmission cost using two approaches. The first uses System R* algorithm approach when the data is of non-skew nature and the second uses SharesSkew algorithm when the data has skews i.e., same value for a specific join attribute, named as Heavy Hitter (HH). Rules of the two algorithms to be followed for performing join are specified and by illustrating with Banking System, the communication cost is evaluated.