简介:Thispaperproposesasemi-greedyframeworkforoptimizingmulti-joinqueriesinshared-nothingsystems.Theplangeneratedbytheframeworkcomprisesseveralpipelines,eachperformingseveraljoins.Theframeworkdeterminesthe“optimal”numberofjoinstobeperformedineachpipeline.Thedecisionsaremadebasedonthecostestimationoftheentireprocessingplan.Twoexistingoptimizationalgorithmsareextendedundertheframework.Ananalyticalmodelispresentedandusedtocomparethequalityofplansproducedbyeachoptimizationalgorithm.Ourstudyshowsthatthenewalgorithmsoutperformtheircounterpartsthatarenotextended.