1. A system that effectuates exact similarity joins between a first and second collection of sets, comprising: a processor; a memory communicatively coupled to the processor, the memory having stored therein computer-executable instructions configured to implement components of the system that effectuates exact similarity joins between the first and second collection of sets, wherein the exact similarity joins produce a correct result and carry specific performance guarantees, the components including: an analysis component that receives the first and second collection of sets and a threshold value and outputs all candidate pairs of sets from the first and second collection of sets based at least in part on a similarity that equals or exceeds the threshold, the analysis component further generating signatures for each of the first and second collection of sets, the signatures being a function of the respective collection of sets and randomization, the analysis component further including: a sizing component that gauges a number of signatures generated for the first and second collection of sets; an effectiveness component that determines a number of false positive candidate pairs and quantifies a degree to which false positives are minimized; and a costing component that computes a total cost for computing the exact similarity joins between the first and second collection of sets.