Using the Power of Two Choices to Improve Bloom Filters

Abstract

We consider the combination of two ideas from the hashing literature: the power of two choices and Bloom filters. Specifically, we show via simulations that, in comparison with a standard Bloom filter, using the power of two choices can yield modest reductions in the false positive probability using the same amount of space and more hashing. While the improvements are sufficiently small that they may not be useful in most practical situations, the combination of ideas is instructive; in particular, it suggests that there may be ways to obtain improved results for Bloom filters while using the same basic approach they employ, as opposed to designing new, more complex data structures for the problem.