HmSearch: an efficient hamming distance query processing algorithm

Hamming distance measures the number of dimensions where two vectors have different values. In applications such as pattern recognition, information retrieval, and databases, we often need to efficiently process Hamming distance query, which retrieves vectors in a database that have no more than k Hamming distance from a given query vector. Existing work on efficient Hamming distance query processing has some of the following limitations, such as only applicable to tiny error threshold values, unable to deal with vectors where the value domain is large, or unable to attain robust performance in the presence of data skew. In this paper, we propose HmSearch, an efficient query processing method for Hamming distance queries that addresses the above-mentioned limitations. Our method is based on improved enumeration-based signatures, enhanced filtering, and the hierarchical binary filtering-and-verification. We also design an effective dimension rearrangement method to deal with data skew. Extensive experimental results demonstrate that our methods outperform state-of-the-art methods by up to two orders of magnitude.