HIGHER-ORDER DATA SKETCHING FOR AD-HOC QUERY ESTIMATION

Technology for using a nested probabilistic data structure to determine properties of a data set. An example method may involve: receiving a data item comprising a first and second item values; accessing a first probabilistic data structure comprising elements with references to a plurality of second probabilistic data structures; evaluating the first probabilistic data structure to identify a set of the second probabilistic data structures, wherein the evaluating comprises applying a set of hash functions to the first item value to generate hash values indicating the set of second probabilistic data structures corresponding to the first item value; evaluating one of the second probabilistic data structures in view of the second item value to identify a set of elements of the second probabilistic data structure corresponding to the second item value; and updating the set of elements of the second probabilistic data structure to represent the data item.