Optimization of multi-join queries in shared-nothing systems

The paper proposes a semi-greedy framework that generates an optimal pipelined plan for multi-join queries. The generated plan comprises several pipelines, each performing several joins. The framework determines the “optimal” number of joins to be performed in each pipeline. The decisions are made based on the cost estimation of the entire processing plan. Two optimisation algorithms are extended under the framework. The study shows that the new algorithms outperform their counterparts that are not extended