Multi-Join Optimization for Symmetric Multiprocessors

This paper looks at the problem of multi-join query optimization for symmetric multiproceasore. Optimizrtlion algorithms based on dynamic programming and greedy heuristics are described that, unlike traditional methods, include memory resources and pipelining in their cost model. An analytical model is presented and used to compare the quality of plans produced by each optimization algorithm. Experimental results show that, while dynamic programming produces the be& plans, simple heuristics often do nearly as well. The came results are also used to highlight the advantages of bushy execution trees over more restricted tree shapes.