1. A non-transitory computer-readable medium storing a program that, when executed by a computing device, causes the computing device to: receive a data item via a network; generate a key based on a subset of data from the received data item; calculate a first transformation action code, the first transformation action code corresponding to a first transformation action in which a first transformation data is inserted into the key to form a first transformed key; calculate a second transformation action code, the second transformation action code corresponding to a second transformation action in which a second transformation data is inserted into the key to form a second transformed key; generate the first transformed key according to the first transformation action code by inserting the first transformation data into the key; generate the second transformed key according to the second transformation action code by inserting the second transformation data into the key; calculate a first hash code based on the first transformed key with a first hash function; calculate a second hash code based on the second transformed key with a second hash function that is orthogonal to the first hash function; insert the data item in a first partition of a hash table in a first location corresponding to the first hash code; and insert the data item in a second partition of the hash table in a second location corresponding to the second hash code.