1. A method comprising: prior to receiving a join query that requires work to be performed on a first set of data that belongs to a first partitioned object that resides on-disk, performing the steps of: pre-loading into volatile memory data from the first partitioned object; wherein the first partitioned object includes a first plurality of partitions; wherein pre-loading the first partitioned object includes: mapping the first plurality of partitions to a plurality of partition groups; wherein each of the plurality of partition groups corresponds to corresponding partition criteria; and assigning each partition group of the plurality of partition groups to a corresponding host node of a plurality of host nodes; pre-loading each given partition of the first plurality of partitions into volatile memory of a host node that corresponds to the partition group to which the given partition is mapped; in response to receiving the join query, distributing work required by the join query to the plurality of host nodes based on which partition groups have been assigned to each of the plurality of host nodes.