1. A system, comprising: a plurality of computing devices configured to implement a distributed MapReduce computation system comprising: one or more master nodes; and one or more worker nodes; wherein the one or more master nodes are configured to: divide a current dataset into a plurality of current partitions; and provide a respective one of one or more previous partitions of a previous dataset and two or more corresponding ones of the current partitions to individual ones of the worker nodes; wherein one or more of the worker nodes are each configured to implement an input function and a map function of the MapReduce computation system; wherein the input function is configured to: iterate through records of the respective previous partition and of the corresponding current partitions; and provide, at each iteration, information regarding a record of the respective previous partition and information regarding a matching record of one of the corresponding current partitions as input to the map function; and wherein the map function is configured to perform a computation on the information regarding the matching records.