Equality testing for complex objects based on hashing

Abstract

An important characteristic of many new data models is the capability of constructing complex data objects. These complex data objects usually include set valued attributes. The efficiency of the implementation of sets heavily depends on the efficiency of the equality operator. In this paper we present algorithms for testing equality of complex objects based on hashing. To evaluate the performance of the two proposed algorithms we made simulations varying the different parameters involved. The first algorithm is based on hash functions and the second is based on a linear ordering. Equality testing based on hashing is considerably better, expecially for large objects. Furthermore, equality testing based on a linear ordering requires preprocessing for maintaining the linear order, whereas in the other case the preprocessing consists solely of calculating the hash values.