Tuning String Matching for Huge Pattern Sets

Abstract

We present three algorithms for exact string matching of multiple patterns. Our algorithms are filtering methods, which apply q- grams and bit parallelism. We ran extensive experiments with them and compared them with various versions of earlier algorithms, e.g. different trie implementations of the Aho-Corasick algorithm. Our algorithms showed to be substantially faster than earlier solutions for sets of 1,000- 100,000 patterns. The gain is due to the improved filtering efficiency caused by q-grams.